Research/Publications

Books

Butler, G & Einarsson, ÓJ 2026, The EFTA Court: Practice and Procedure. Elgar European Law and Practice series, Edward Elgar Publishing, Cheltenham.

Butler, G 2026, Micro-states of Europe and their Legal Relations with the European Union, Kluwer Law International: Alphen aan den Rijn.

Butler, G (ed) 2025, Research Handbook on EEA Internal Market Law, Research Handbooks in European Law, Edward Elgar Publishing: Cheltenham. ISBN (Print): 9781803922454 (978-1-80392-245-4).

Groussot, X, Öberg, M-L, Butler, G (eds) 2025, The EU Law of Investment: Past, Present, and Future, Swedish Studies in European Law, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509965854 (978-1-50996-585-4).

Butler, G & Lazowski, A (eds) 2022, Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). DOI: 10.5040/9781509950034. More here.

Butler, G & Wessel, RA (eds) 2022, EU External Relations Law: The Cases in Context, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509939695 (978-1-5099-3969-5). ISBN (Electroninc): 9781509939701 (978-1-5099-3970-1), 9781509939718 (978-1-5099-3971-8), 9781509939725 (978-1-5099-3972-5). 1048 pp. DOI: 10.5040/9781509939725. More here.

Cited in:

• Opinion of Advocate General Nicholas Emiliou in Case C‑516/22, European Commission v United Kingdom of Great Britain and Northern Ireland (Judgment of the UK Supreme Court) ECLI:EU:C:2023:857, Court of Justice of the European Union, 9 November 2023. (Fifth Chamber).

Butler, G 2019, Constitutional Law of the EU’s Common Foreign and Security Policy: Competence and Institutions in External Relations. Modern Studies in European Law series, Hart Publishing/Bloomsbury, Oxford. ISBN (Hardback): 978-1-50992-594-0 (9781509925940). ISBN (PDF): 978-1-50992-596-4 (9781509925964). ISBN (epub): 978-1-50992-595-7 (9781509925957). Online: 978-1-50992-597-1 (9781509925971). More here.

Cited in:

• Opinion of Advocate General Evgeni Tanchev, Case C-730/18 P, SC v Eulex Kosovo, ECLI:EU:C:2020:176, Court of Justice of the European Union, 5 March 2020 (First Chamber case).

• Opinion of Advocate General Gerard Hogan, Case C‑134/19 P, Bank Refah Kargaran v Council of the European Union, ECLI:EU:C:2020:396, Court of Justice of the European Union, 28 May 2020 (Grand Chamber case).

• Opinion of Advocate General Evgeni Tanchev, Case C‑283/20, CO, ME, GC and 42 Others v MJ (Head of Mission), European Commission, European External Action Service (EEAS), Council of the European Union, Eulex Kosovo, ECLI:EU:C:2021:781, Court of Justice of the European Union, 30 September 2021 (Fifth Chamber case).

• Opinion of Advocate General Tamara Ćapeta in Joined Cases C‑29/22 P and C‑44/22 P, KS, KD v Council of the European Union, European Commission, and European External Action Service (EEAS), and European Commission v KS, KD, Council of the European Union, and European External Action Service (EEAS), ECLI:EU:C:2023:901, Court of Justice of the European Union, 23 November 2023 (Grand Chamber case).

Articles and chapters

Butler, G 2026, Humanitarian Aid and the CFSP. in S. Blockmans & P. Koutrakos (eds), Research Handbook on the EU’s Common Foreign and Security Policy. Second Edition, Edward Elgar Publishing: Cheltenham.

Butler, G 2026, Vienna Convention on Diplomatic Relations. in M. E. McGuinness, R. A. Wessel, M. Jorgensen (eds), Elgar Encyclopedia of Law and Diplomacy. Edward Elgar Publishing: Cheltenham.

Butler, G 2025, Free Movement of Capital: General Rules and Exceptions. in R. Schütze & T. Tridimas (eds), Oxford Principles of European Union Law: Volume II: The Internal Market, Oxford University Press: Oxford.

Butler, G 2025, State Monopolies of a Commercial Character. in R. Schütze & T. Tridimas (eds), Oxford Principles of European Union Law: Volume II: The Internal Market, Oxford University Press: Oxford.

Butler, G 2025, ‘Deposit return schemes of EU Member States and the EU’s internal market’ Review of European, Comparative & International Environmental Law, vol. 34. DOI: 10.1002/REEL.12591.

Butler, G 2025, Deciding Not to Decide: Dismissal, Narrowing, and Relinquishment at the Court of Justice of the European Union. Normative Assessment of the ECJ Reasoning.

Butler, G 2025, ‘At the Heart of Legal Europe? Member States and their Relationship to the EU Legal Order’ Dublin University Law Journal, vol. 44.

Butler, G 2025, ‘Adjudicating in the Atmosphere: the Appeals Board of the European Organisation for the Exploitation of Meteorological Satellites’ TBC.

Butler, G 2025, Research, Knowledge, Science, and Education. in J. Odermatt & R.A. Wessel (eds), Research Handbook on EU Law and Global Challenges, Edward Elgar Publishing: Cheltenham.

Butler, G 2025, ‘The Legal Relations of the European Union with the Principality of Andorra’ European Foreign Affairs Review, vol. 30.

Butler, G 2025, Charlemagne. in I. Dale (ed), The Generals, Hodder & Stoughton/Hachette: London

Butler, G 2025, The High Representative as new actor before the Court of Justice of the European Union. in, TBC.

Butler, G 2025, ‘Offsetting Dividend Taxation through Corporate Taxation for Resident Undertakings and the Free Movement of Capital’ European Taxation, vol. 65, no. 1.

Butler, G (ed) 2025, Research Handbook on EEA Internal Market Law, Research Handbooks in European Law, Edward Elgar Publishing: Cheltenham. ISBN (Print): 9781803922454 (978-1-80392-245-4).

Butler, G 2025, Intellectual Property. in G. Butler (ed), Research Handbook on EEA Internal Market Law, Research Handbooks in European Law, Edward Elgar Publishing: Cheltenham. ISBN (Print): 9781803922454 (978-1-80392-245-4).

Butler, G 2025, The EEA Agreement: On Thirty Years of an Extended Internal Market. in G. Butler (ed), Research Handbook on EEA Internal Market Law, Research Handbooks in European Law, Edward Elgar Publishing: Cheltenham. ISBN (Print): 9781803922454 (978-1-80392-245-4).

Butler, G 2025, Screening of Foreign Direct Investment and the Common Commercial Policy. in X. Groussot, M.-L. Öberg, & G. Butler (eds), The EU Law of Investment: Past, Present, and Future, Hart Publishing/Bloomsbury: Oxford.

Groussot, X, Öberg, M-L, Butler, G (eds) 2025, The EU Law of Investment: Past, Present, and Future, Swedish Studies in European Law, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509965854 (978-1-50996-585-4).

Butler, G 2024, ‘Solidarity on Trial: On Reliance, Reason, and Logic at the Court of Justice of the EU’ Maastricht Journal of European and Comparative Law, vol. 31.

Butler, G & Krunke, H (eds) 2024, Nordic Cooperation and the European Union: 50 Years of Legal Integration, Hart Publishing/Bloomsbury: Oxford.

Butler, G 2024, ‘Free Movement of Banks, Deposit Guarantee Schemes, and Dispute Resolution within the EU’ Europarättslig Tidskrift, vol. 27. no. 4. pp. 589-608. DOI: 10.53292/445d5b7b.45c97f88

Butler, G 2024, Nordic-EU Legal Integration: The Ins and the Outs. in G. Butler & H. Krunke (eds), Nordic Cooperation and the European Union: 50 Years of Legal Integration, Hart Publishing/Bloomsbury: Oxford.

Butler, G 2024, Actors in EU External Relations. in A. Biondi & O Stefan (eds) Elgar Encyclopedia of EU Law. Edward Elgar Publishing, Cheltenham.

Butler, G 2024, ‘Public Pension Funds in EU Member States: Their Comparability and Tax Treatment under the Free Movement of Capital’ European Taxation, vol. 64, no. 11. pp. 526-529. DOI: 10.59403/37tt4vb.

Butler, G 2024, ‘Pant- og retursystem: prisfastsættelse, grænseoverskridende handel og privat eksport inden for EU’s indre marked’ EU-ret og Menneskeret, vol. 31. no. 2. pp. 137-149.

Butler, G 2024, Fisheries: The Cod’s Pollocks or a Damp Squid. in F. Fabbrini (ed), The Law and Politics of Brexit: Volume V: The EU-UK Trade and Cooperation Agreement, Oxford University Press: Oxford. ISBN (Print): 9780198908289 (978-0-198-90828-9). ISBN (Electronic): 9780198908319 (978-0-198-90831-9). pp. 167-181. DOI: 10.1093/oso/9780198908289.003.0009.

Butler, G 2024 ‘Sun from Behind the Clouds: the Appeals Board of the European Centre for Medium-Range Weather Forecasts’ Journal of International Dispute Settlement, Oxford University Press, vol. 15. no. 3. pp. 365-376. DOI: 10.1093/jnlids/idae013.

Butler, G 2024, An Advocate before Advocate General: Eleanor Sharpston at the European Courts. in C. Barnard, A. Lazowski, D. Sarmiento, (eds), Pursuit of Legal Harmony in a Turbulent Europe: Essays in Honour of Eleanor Sharpston, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509977000 (978-1-509-97700-0). ISBN (Electronic): 9781509977017 (978-1-509-97701-7), 9781509977024 (978-1-509-97702-4), 9781509977031 (978-1-50997-703-1). pp. 11-28. DOI: 10.5040/9781509977031.ch-003.

Butler, G 2024 ‘The Legal Relations of the European Union with the Republic of San Marino’ European Foreign Affairs Review, vol. 29. no. 3. pp. 247-274. DOI: 10.54648/eerr2024012.

Butler, G 2024 ‘Leaps in Time through the EU’s Common Foreign and Security Policy Post-Enlargement’ EU Law Live, 20 June 2024.

Butler, G 2024, The Representative of the Crown and the Governor-General of the Irish Free State: Text and Context. in L. Cahillane & D. K. Coffey (eds), The Centenary of the Irish Free State Constitution: Constituting a Polity?, Palgrave Modern Legal History, Palgrave Macmillan: London. ISBN (Print): 9783031461804 (978-3-031-46180-4). ISBN (Print): 9783031461835 (978-3-031-46183-5). ISBN (Electronic): 9783031461811 (978-3-031-46181-1). pp. 91-111. DOI: 10.1007/978-3-031-46181-1_6.

Butler, G 2024, ‘The Administrative Tribunal of the European Stability Mechanism: ESMAT at 10’ International Journal of Comparative Labour Law and Industrial Relations, vol. 40. no. 3. pp. 329-346.

Butler, G 2024, Reform of the Judicial Architecture of the EFTA Pillar of the EEA. in P. Hreinsson, O.J. Einarsson, & B Pálmarsdóttir (eds), The EFTA Court: Developing the EEA over Three Decades, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509968800 (978-1-509-96880-0). ISBN (Electronic): 9781509968817 (978-1-509-96881-7), 9781509968824 (978-1-509-96882-4), 9781509968831 (978-1-50996-883-1). pp. 75-94. DOI: 10.5040/9781509968831.ch-006.

Cotter, J & Butler, G 2024 ‘The President of the European Commission and the Power to Request a Commissioner’s Resignation’ Common Market Law Review, vol. 61. no. 3, pp. 593–622. DOI: 10.54648/cola2024044.

Butler, G 2023, ‘Of Rulers, Relatives, and Businesspersons: The Imposition of Sanctions on Family Members’ Legal Issues of Economic Integration, vol. 50, no. 4. pp. 367-390. DOI: 10.54648/leie2023024.

Butler, G 2023, ‘Jurisdiction of the EU Courts in the Common Foreign and Security Policy: Reflections on the Opinions of AG Ćapeta in KS and KD, and Neves 77 Solutions’, EU Law Live, 26 November 2023.

Butler, G 2023, ‘EU agencies within the common foreign, security, and defence policies’ EU Law Live, 2 October 2023.

Ørum, J & Butler, G 2023, ‘The Market Distortion Provisions as a Legal Basis for Tax Harmonisation in EU Law’ European Law Review, vol. 48, no. 1, pp. 103-116.

Butler, G 2023, EU Regulations in the National Legal Order in A. Lazowski & A Sikora (eds), EU Regulations in Practice: Legislative and Judicial Approaches, Hart Publishing/Bloomsbury: Oxford.

Butler, G 2023, ‘Reimaging the Law on Alcoholic Goods in Sweden’ Europarättslig Tidskrift, vol. 26. no. 3. pp. 531-543.

Butler, G 2023, State Monopolies of a Commercial Character. in S. Garben & L. Gormley (eds), Oxford Encyclopedia of EU Law. Oxford University Press, Oxford. ISBN: 9780191877025 (978-01-91877-02-5).

Butler, G 2023, ‘Contracted EU civil servants in EU common security and defence policy missions: Procedural routes to judicial remedies’ European Labour Law Journal, vol. 14, no. 3. pp. 353-375. DOI: 10.1177/20319525231177001.

Butler, G, 2023 ‘The Legal Relations of the European Union with the Principality of Monaco’ European Foreign Affairs Review, vol. 28. no. 3. pp. 259-282. DOI: 10.54648/eerr2023021.

Butler G 2023, ‘Sweden and the Free Movement of Alcoholic Goods in the EU Internal Market’ European Public Law, vol. 29. no. 3. pp. 75-114. DOI: 10.54648/euro2023005.

Butler, G 2023, Public and private enforcement possibilities within the EU’s Common Foreign and Security Policy. in M. Scholten (ed), Research Handbook on the Enforcement of EU Law, Edward Elgar Publishing: Cheltenham. ISBN (Print): 9781802208023 (978-1-80220-802-3). pp. 199-214. DOI: 10.4337/9781802208030.00023.

Butler, G 2023, Free Movement of Persons in the Nordic States through EU Law and EEA Law. in K. Hyltén-Cavallius & J. Paju (eds), Free Movement of Persons in the Nordic States: EU Law, EEA Law, and Regional Cooperation, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509951840 (978-1-5099-5184-0). ISBN (Electronic): 9781509951857 (978-1-5099-5185-7), 9781509951864 (978-1-5099-5186-4), 9781509951871 (978-1-5099-5187-1). pp. 31-54. DOI: 10.5040/9781509951871.ch-003.

Butler, G 2023, Tribunals in the Nordic States and Referrals to the European Courts. in J. Reichel & M. Zamboni (eds), Scandinavian Studies in Law: Volume 69 – Rule of Law, Jure: Stockholm. ISBN (Print): 9789185142828. pp. 145-176. DOI: 10.53292/32f26f7c.398102c0.

Butler, G 2023, EU Internal Market Law, Elgar European Law series, Edward Elgar Publishing: Cheltenham.

Butler, G & Lazowski, A (eds) 2022, Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). DOI: 10.5040/9781509950034.

Butler, G 2022, Alcoholic Goods and Sweden: The EU Law of Private Imports, Retail Sale, and State Monopolies, Swedish Institute for European Policy Studies: Stockholm. ISBN (Print/Online): 9789189498044 (978-91-89498-04-4).

Butler, G 2022, ‘Governors and former Governors of National Central Banks, and their Privileges and Immunities under EU Law’ Journal of International Banking Law and Regulation, vol. 37, no. 9, pp. 327-330.

Butler, G & Meling, M 2022, ‘State Monopolies and the Free Movement of Goods in EEA Law: Ensuring Substantive Homogeneity at the EFTA Court’ International Trade Law and Regulation, vol. 28, no. 1, pp. 55-72.

Butler, G 2022, Reconciling the Special Provision on State Monopolies with the General Provisions on the Free Movement of Goods: Opinion of Advocate General Warner in Manghera. in G. Butler & A. Lazowski (eds), Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). pp. 89-101. DOI: 10.5040/9781509950034.ch-008.

Ward, A & Butler, G 2022, The Relationship between the Action for Annulment and Preliminary Reference Procedures: Opinion of Advocate General Jacobs in TWD. in G. Butler & A. Lazowski (eds), Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). pp. 295-310. DOI: 10.5040/9781509950034.ch-027.

Butler, G 2022, Free Movement of Goods and the Public Security Exception: Opinion of Advocate General Slynn in Campus Oil. in G. Butler & A. Lazowski (eds), Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). pp. 187-198. DOI: 10.5040/9781509950034.ch-017.

Butler, G & Lazowski, A 2022, Let’s Take the Canvass Out: Advocates General at the Court of Justice of the European Union. in G. Butler & A. Lazowski (eds), Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). pp. 7-18. DOI: 10.5040/9781509950034.ch-001.

Butler, G & Lazowski, A 2022, Neither Advocates, Nor Generals: The UK Advocates General and the Shaping of EU Law. in G. Butler & A. Lazowski (eds), Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). pp. 607-622. 10.5040/9781509950034.ch-053.

Butler, G & Lazowski, A 2022, Introduction. in G. Butler & A. Lazowski (eds), Shaping EU Law the British Way: UK Advocates General at the Court of Justice of the European Union, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509950003 (978-1-5099-5000-3). ISBN (Electronic): 9781509950010 (978-1-5099-5001-0), 9781509950027 (978-1-5099-5002-7), 9781509950034 (978-1-5099-5003-4). pp. 1-4. DOI: 10.5040/9781509950034.0008.

Butler, G 2022, ‘The Legal Relations of the European Union with the Vatican City State and Holy See’ European Foreign Affairs Review, vol. 27, no. 2, pp. 263-282.

Butler, G & Sørensen, K.E. 2022, The Prohibition of Abuse of EU Law: A Special General Principle. in K. S. Ziegler, P. J. Neuvonen, & V. Moreno-Lax (eds), Research Handbook on General Principles in EU Law: Constructing Legal Orders in Europe, Research Handbooks in European Law, Edward Elgar: Cheltenham. ISBN (Print): 9781784712372 (978-1-7847-1237-2). ISBN (Electronic): 9781784712389 (978-1-7847-1238-9). pp. 402-422. DOI: 10.4337/9781784712389.00033.

Cited in:

• Opinion of Advocate General Maciej Szpunar in Case C‑236/23, Mutuelle assurance des travailleurs mutualistes (Matmut) v TN, Société MAAF assurances, Fonds de garantie des assurances obligatoires de dommages (FGAO), PQ, ECLI:EU:C:2024:560, Court of Justice of the European Union, 27 June 2024. (First Chamber).

Butler, G 2022, The Creation of an Internal Market for Private Pensions: Legal Design, Mobility, Retirement, and Taxation, EU Law Live, Weekend Edition, vol. 101, pp. 2-10.

Butler, G 2022, State Aid: Extension of the Acquis and the ‘Effect on Trade’. in F. Fabbrini (ed), The Law and Politics of Brexit: Volume IV: Protocol on Ireland/Northern Ireland, Oxford University Press: Oxford. ISBN (Print, hardback): 9780192863935 (978-0-1928-6393-5), ISBN (Print, paperback): 9780192863942 (978-0-1928-6394-2). ISBN (Electronic): 9780191954528 (978-0-1919-5452-8), 9780192678782 (978-0-1926-7878-2), 9780192678799 (978-0-1926-7879-9). pp. 185-208.

Butler, G 2022, The EU Customs Union, International Agreements of EU Member States, and the Doctrine of Substitution: Nederlandse Spoorwegen. in G. Butler & R. A. Wessel (eds), EU External Relations Law: The Cases in Context, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509939695 (978-1-5099-3969-5). ISBN (Electronic): 9781509939701 (978-1-5099-3970-1), 9781509939718 (978-1-5099-3971-8), 9781509939725 (978-1-5099-3972-5). pp. 57-66. DOI: 10.5040/9781509939725.ch-005.

Butler, G & Wessel, RA 2022, Jurisdiction of the Court for Non-contractual Liability and Actions for Damages Claims within the CFSP: Bank Refah Kargaran. in G. Butler & R. A. Wessel (eds), EU External Relations Law: The Cases in Context, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509939695 (978-1-5099-3969-5). ISBN (Electronic): 9781509939701 (978-1-5099-3970-1), 9781509939718 (978-1-5099-3971-8), 9781509939725 (978-1-5099-3972-5). pp. 991-1000. DOI: 10.5040/9781509939725.ch-091.

Butler, G & Wessel, RA 2022, EU External Relations Law, and Navigating the Case Law of the Court of Justice of the European Union. in G. Butler & R. A. Wessel (eds), EU External Relations Law: The Cases in Context, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509939695 (978-1-5099-3969-5). ISBN (Electronic): 9781509939701 (978-1-5099-3970-1), 9781509939718 (978-1-5099-3971-8), 9781509939725 (978-1-5099-3972-5). pp. 1-8. DOI: 10.5040/9781509939725.0006.

Butler, G & Wessel, RA (eds) 2022, EU External Relations Law: The Cases in Context, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509939695 (978-1-5099-3969-5). ISBN (Electroninc): 9781509939701 (978-1-5099-3970-1), 9781509939718 (978-1-5099-3971-8), 9781509939725 (978-1-5099-3972-5). 1048 pp. DOI: 10.5040/9781509939725.

Cited in:

• Opinion of Advocate General Nicholas Emiliou in Case C‑516/22, European Commission v United Kingdom of Great Britain and Northern Ireland (Judgment of the UK Supreme Court) ECLI:EU:C:2023:857, Court of Justice of the European Union, 9 November 2023. (Fifth Chamber).

Butler, G 2022, The EU Customs Union, Free Movement of Goods, and Enforcement Mechanisms in the Protocol on Northern Ireland: A Legal Appraisal. in A. Lazowski & A. Cygan (eds). Research Handbook on Legal Aspects of Brexit, Research Handbooks in European Law, Edward Elgar: Cheltenham. ISBN (Print): 9781800373136 (978-1-80037-313-6). ISBN (Electronic):
978-1-80037-314-3. pp. 175-197. DOI: 10.4337/9781800373143.00016.

Butler, G 2022, Hidden Administrative Review in EU Law: The BoAs of EU Agencies in the Common Foreign and Security Policy. in M. Chamon, A. Volpato & M. Eliantonio (eds), Boards of Appeal of EU Agencies: Towards Judicialization of Administrative Review?, Oxford University Press: Oxford. ISBN (Print): 9780192849298 (978-0-1928-4929-8). ISBN (Electronic): 9780192665973 (978-0-1926-6597-3). pp. 122-150. DOI: 10.1093/oso/9780192849298.003.0007.

Butler, G 2022, Max Sørensen (1913-1981): From Diplomat to Professor to Judge of the Court of Justice of the European Communities. in S. Vogenauer & P. Bajon (eds), Key Biographies in the Legal History of the European Union (1950-1993).

Kassoti, E & Butler, G 2022, The Approach of the CJEU to International Law: Towards a Context-Specific Approach. in E. Fahey & I. Mancini (eds), Understanding the EU as a Good Global Actor: Ambitions, Values, and Metrics, Edward Elgar Publishing: Cheltenham. ISBN (Print): 9781802202977 (978-1-8022-0297-7). ISBN (Electronic): 9781802202984 (978-1-8022-0298-4). pp. 261-276. DOI: 10.4337/9781802202984.00025.

Neergaard, U & Butler, G 2022, Denmark’s Defence Opt-out, the Forthcoming Referendum, and the Changing Face of EU Defence and Security Arrangements, EU Law Live, Weekend Edition, vol. 95, pp. 2-11.

Butler, G 2022, The Acceptance, Incorporation, and Re-translation of European Union law. in B. Davies, & F. Nicola (eds), EU Law Stories II: Re-translating European Legal Concepts into Domestic Legal Contexts, Cambridge University Press: Cambridge.

Butler, G 2022, ‘EU Secondary Law Unable to Impose Unanimity within the Council for Modifying/Amending EU International Agreements: Commission v Council (South Korea)’ EU Law Live, 16 March 2022.

Kochenov, D & Butler, G 2021, ‘Independence of the Court of Justice of the European Union: Unchecked Member States power after the Sharpston Affair’ European Law Journal, vol. 27, nos. 1-3, pp. 262-296. DOI: 10.1111/eulj.12434.

Butler, G 2021, ‘Lower Instance National Courts and Tribunals in Member States and Their Judicial Dialogue with the Court of Justice of the European Union’ Nordic Journal of European Law, vol. 4, no. 2, pp. 19-36. DOI: 10.36969/njel.v4i2.23779.

Butler, G 2021, ‘Immunities of national central banks in Member States under EU law: Commission v Slovenia (ECB Archives)’ Common Market Law Review, vol. 58. no. 6, pp. 1895-1916.

Butler, G 2021, ‘The Modification/Amendment of EU International Agreements – Unanimous or Qualified Majority Decision-making? The Opinion of AG Richard de la Tour in Commission v Council (South Korea)’ EU Law Live, 2 November 2021.

Butler, G 2021, ‘The EU’s Contractual Relations and the Arbitration Clause: Disputes at the Court of Justice of the European Union’ European Law Review, vol. 46. no. 3. pp. 345-363.

Butler, G 2021, ‘State Monopolies and the Free Movement of Goods in EU Law: Getting Beyond Obscure Clarity’ Legal Issues of Economic Integration, vol. 48, no. 3, pp. 285-308.

Butler, G 2021, The Balance of Powers and the EU’s Common Foreign and Security Policy, in D. Fromage, & A. Herranz-Surrallés (eds), Executive-Legislative (Im)balance in the European Union, Parliamentary Democracy in Europe, Hart Publishing: Oxford. ISBN (Print): 9781509930005 (978-1-50993-000-5). ISBN (Electronic): 9781509930036 (978-1-50993-003-6), 9781509930029 (978-1-50993-002-9), 9781509930012 (978-1-50993-001-2). pp. 263-284. DOI: 10.5040/9781509930036.ch-015.

Butler, G 2021, The European Rule of Law Standard, the Nordic States, and EU Law. in A. Bakardjieva Engelbrekt, A. Moberg, & J. Nergelius (eds), Rule of Law in the EU: 30 Years After the Fall of the Berlin Wall, Hart Publishing/Bloomsbury: Oxford. ISBN (Print): 9781509941599 (978-1-5099-4159-9). ISBN (Electronic): 9781509941605, (978-1-5099-4160-5), 9781509941612 (978-1-5099-4161-2). pp. 243-264. DOI: 10.5040/9781509941629.ch-011.

Butler, G 2021 ‘Private Pensions and EU Internal Market Law: Enhancing Retirement Provision through Harmonisation’ European Business Law Review, vol. 32, no. 2. pp. 853-876.

Butler, G & Wessel RA 2021, Happy birthday ERTA! 50 Years of the Implied External Powers Doctrine in EU Law, European Law Blog, 31 March 2021. URL: https://europeanlawblog.eu/2021/03/31/happy-birthday-erta-50-years-of-the-implied-external-powers-doctrine-in-eu-law/

Butler, G & Meling, M 2020, ‘Horizontal Direct Effect of the Charter in EU Law: Ramifications for the European Economic Area’ Nordic Journal of European Law, vol. 3, no. 2. pp. 1-27. DOI: 10.36969/njel.v3i2.22389

Kochenov, D & Butler, G 2020 ‘The Independence and Lawful Composition of the Court of Justice of the European Union: Replacement of Advocate General Sharpston and the Battle for the Integrity of the Institution’ in J.H.H. Weiler & G. de Búrca (eds), Jean Monnet Working Paper series, Jean Monnet Center for International and Regional Economic Law & Justice, School of Law, New York University: New York. ISSN: 2161-0320.

Butler, G 2020 ‘Mind the (Homogeneity) Gap: Independence of Referring Bodies Requesting Advisory Opinions from the EFTA Court’ Fordham International Law Journal, vol. 44, no. 2, pp. 307-352.

Butler, G 2020 ‘The Future of EU International Agreements as Legal Instruments in the ASEAN Region’ Journal of International and Comparative Law, vol. 7, no. 2, pp. 287-305.

Butler, G 2020 ‘Independence of non-judicial bodies and orders for a preliminary reference to the Court of Justice’ European Law Review, vol. 45, no. 6, pp. 870-887.

Butler, G & Cotter J 2020 ‘Just Say No! Appeals Against Orders for a Preliminary Reference' European Public Law, vol. 26, no. 3, pp. 615-642.

Butler, G 2020 ‘The European Defence Union and Denmark’s Defence Opt-out’ European Foreign Affairs Review, vol. 25, no. 1, pp. 117-150.

Butler, G. & Snaith, H 2020, Negative Solidarity: The European Union and the Financial Crisis. in H. Krunke, H. Petersen, & I. Manner (eds), Transnational Solidarity: Concept, Challenges and Opportunities, Cambridge University Press: Cambridge. ISBN (Print): 9781108487368 (978-1-1084-8736-8). ISBN (Electronic): 9781108766593 (9781-1-087-6659-3). pp. 128-164. DOI: 10.1017/9781108766593.009.

Butler, G 2020 ‘An Interim Post-mortem: Specialised Courts in the EU Judicial Architecture after the Civil Service Tribunal’ International Organizations Law Review, vol. 17, no. 3. pp. 586-632. DOI: 10.1163/15723747-2019010.

Banke, C. F. S., Nissen, C., Schmidt, J. L., Olesen, M. R., Mouritzen, H., Rahbek-Clemmensen, J., Pedersen, R. B., Butler, G., Andersen, L. R. 2020 European Defence Cooperation and the Danish Defence Opt-out: Report on the developments in the EU and Europe in the field of security and defence policy and their implications for Denmark (Europæisk forsvarssamarbejde og det danske forsvarsforbehold: Udredning om udviklingen i EU og Europa på det sikkerheds- og forsvarspolitiske område og betydningen for Danmark). København Copenhagen (København): Danish Institute for International Studies (Dansk Institut for Internationale Studier). ISBN: 978877605999 (978-87-7605-999). 108 pp.

Banke, C. F. S., Nissen, C., Schmidt, J. L., Olesen, M. R., Mouritzen, H., Rahbek-Clemmensen, J., Pedersen, R. B., Butler, G., Andersen, L. R. 2019 Europæisk forsvarssamarbejde og det danske forsvarsforbehold: Udredning om udviklingen i EU og Europa på det sikkerheds- og forsvarspolitiske område og betydningen for Danmark (European Defence Cooperation and the Danish Defence Reservation: Investigation on developments in the EU and Europe in the field of security and defence policy and the importance for Denmark). København (Copenhagen): Dansk Institut for Internationale Studier (Danish Institute for International Studies). ISBN (Print): 9788776059859 (978-8-7760-5985-9). ISBN (Electronic): 9788776059866 (978-8-7760-5986-6). 108 pp.

Butler, G 2019, Constitutional Law of the EU’s Common Foreign and Security Policy: Competence and Institutions in External Relations. Modern Studies in European Law series, Hart Publishing/Bloomsbury, Oxford. ISBN (Hardback): 978-1-50992-594-0 (9781509925940). ISBN (PDF): 978-1-50992-596-4 (9781509925964). ISBN (epub): 978-1-50992-595-7 (9781509925957). Online: 978-1-50992-597-1 (9781509925971).

Cited in:

• Opinion of Advocate General Evgeni Tanchev, Case C-730/18 P, SC v Eulex Kosovo, ECLI:EU:C:2020:176, Court of Justice of the European Union, 5 March 2020 (First Chamber case).

• Opinion of Advocate General Gerard Hogan, Case C‑134/19 P, Bank Refah Kargaran v Council of the European Union, ECLI:EU:C:2020:396, Court of Justice of the European Union, 28 May 2020 (Grand Chamber case).

• Opinion of Advocate General Evgeni Tanchev, Case C‑283/20, CO, ME, GC and 42 Others v MJ (Head of Mission), European Commission, European External Action Service (EEAS), Council of the European Union, Eulex Kosovo, ECLI:EU:C:2021:781, Court of Justice of the European Union, 30 September 2021 (Fifth Chamber case).

• Opinion of Advocate General Tamara Ćapeta in Joined Cases C‑29/22 P and C‑44/22 P, KS, KD v Council of the European Union, European Commission, and European External Action Service (EEAS), and European Commission v KS, KD, Council of the European Union, and European External Action Service (EEAS), ECLI:EU:C:2023:901, Court of Justice of the European Union, 23 November 2023 (Grand Chamber case).

Butler, G 2019, The EU Flexibility Clause is Dead, Long Live the EU Flexibility Clause. in A. Bakardjieva Engelbrekt, & X. Groussot (eds), The Future of Europe: Political and Legal Integration Beyond Brexit, Swedish Studies in European Law, Hart Publishing: Oxford. ISBN (Print): 9781509923304 (978-1-5099-2330-4). ISBN (Electronic): 9781509923311 (978-1-5099-2331-1), 9781509923328 (978-1-5099-2332-8), 9781509923335 (978-1-50992-333-5). pp. 63-95. DOI: 10.5040/9781509923335.ch-003.

Butler, G 2019, United Nations Educational, Scientific and Cultural Organization (UNESCO): The EU’s transition from observer to full participant on an ad hoc basis. in R.A. Wessel, & J. Odermatt (eds), Research Handbook on the European Union and International Organizations, Research Handbooks in International Law, Edward Elgar: Cheltenham. ISBN (Print): 9781786438928 (978-1-78643-892-8). ISBN (Electronic): 9781786438935 (978-1-78643-893-5). pp. 142-164. DOI: 10.4337/9781786438935.00014.

Butler, G 2019, Solidaritet og dets grænser for økonomisk integration i EU’s indre marked, EU-ret & Menneskeret, vol. 26, no. 3, pp. 3-27.

Butler, G 2019, Chambers of Deputies. in R Grote, F Lachenmann & R Wolfrum (eds), Max Planck Encyclopedia of Comparative Constitutional Law. Oxford University Press, Oxford. DOI: 10.1093/law-mpeccol/law-mpeccol-e218.

Butler, G & Sadl, U 2018, 'The Preliminaries of a Reference' European Law Review, vol. 43, no. 1, pp. 120-128.

Butler, G 2018, Pre-Ratification Judicial Review of International Agreements to be Concluded by the European Union. in M. Derlén & J. Lindholm (eds), The Court of Justice of the European Union: Multidisciplinary Perspectives, Swedish Studies in European Law, Hart Publishing: Oxford. ISBN (Print): 9781509919086 (978-1-5099-1908-6). ISBN (Electronic): 9781509919093 (978-1-5099-1909-3), 9781509919109 (978-1-5099-1910-9). pp. 53-77.  DOI: 10.5040/9781509919116.ch-004.

Butler, G & Barrett, G 2018 'Europe’s ‘Other’ Open-Border Zone: The Common Travel Area under the Shadow of Brexit' Cambridge Yearbook of European Legal Studies, vol. 20 no. 1, pp. 252-286. DOI: 10.1017/cel.2018.10.

Butler, G 2018 'Solidarity and its limits for economic integration in the European Union’s internal market' Maastricht Journal of European and Comparative Law, vol. 25, no. 3, pp. 310-331. DOI: 10.1177/1023263X18769207.

Butler, G 2018, 'Legal Responses to the European Union’s Migration Crisis' San Diego International Law Journal, vol. 19, no. 2, pp. 277-310. 

Butler, G 2018, 'In Search of the Political Question Doctrine in EU Law', Legal Issues of Economic Integration, vol. 45, no. 4, 329-354. 

Cited in:

• Opinion of Advocate General Michal Bobek, Case C-418/18 P, Puppinck and Others v European Commission, ECLI:EU:C:2019:640, Court of Justice of the European Union (Grand Chamber case).

Butler, G 2018, 'Tvistbilæggelse mellem EU-medlemsstaterne ved Den Europæiske Unions Domstol' Europarättslig Tidskrift, vol. 21, no. 1, pp. 57-74. 

Butler, G 2018, EU Foreign Policy and Other EU External Relations in Times of Crisis: Forcing the Law to Overlap? in E. Kużelewska, A. Weatherburn, D. Kloza (eds), Irregular Migration as a Challenge for Democracy, European Integration and Democracy, Intersentia: Cambridge. ISBN: 978-1-7806-8622-6. pp. 51-81. DOI: 10.1017/9781780687025.005.

Butler, G. 2018, A post-national legal order: Does the European Union have an imposed constitution?. in R. Albert, X. Contiades, A. Fotiadou (eds), The Law and Legitimacy of Imposed Constitutions, Comparative Constitutional Change, Routledge: Abingdon. ISBN (Print): 9781138488984 (978-1-1384-8898-4), 9780367519926 (978-0-3675-1992-6). ISBN (Electronic): 9781351038980 (978-1-351-03898-0), pp. 227-242.

Butler, G 2018, 'Implementing a Complete System of Legal Remedies in EU Foreign Affairs Law' Columbia Journal of European Law, vol. 24, no. 3, pp. 637-676. 

Butler, G 2017 'The Court of Justice as an inter-state court' Yearbook of European Law, vol. 36, no. 1, pp. 179-208. DOI: 10.1093/yel/yex014. 

Cited in:

• Opinion of Advocate General Priit Pikamäe, Case C-121/21, Czech Republic v Poland, ECLI:EU:C:2022:74, Court of Justice of the European Union (Grand Chamber case) (Túrow Mine).

Butler, G 2017 'The Coming of Age of the Court’s Jurisdiction in the Common Foreign and Security Policy' European Constitutional Law Review, vol 13, no. 4, pp. 673-703. DOI: 10.1017/S1574019617000268. 

Butler, G. 2017, The European Union and Diplomatic Law: An Emerging Actor in Twenty-First Century Diplomacy. in P. Behrens (ed.), Diplomatic Law in a New Millennium. Oxford University Press, Oxford. ISBN: 9780198795940 (978-0-19-879594-0). pp. 319-340. DOI: 10.1093/oso/9780198795940.003.0018.

Butler, G 2017 'Standing the Test of Time: Reference for a Preliminary Ruling' Irish Journal of European Law, vol 20 no. 1, pp. 103-116. Link: isel.ie/article/view-free/id/229.

Butler, G 2017, 'A Question of Jurisdiction: Art. 267 TFEU Preliminary References of a CFSP Nature', European Papers, vol 2, no. 1, pp. 201-208. DOI: 10.15166/2499-8249/127. 

Butler, G. & Jensen, M.D., 2017, Storbritanniens had-kærlighedsforhold til Den Europæiske Union (The United Kingdom's Love-Hate Relationship with the European Union). in C.H. Grøn (ed), Politologisk Årbog 2016-2017 (Political Science Yearbook 2016-2017). Hans Reitzels Forlag, Copenhagen. ISBN-10: 8741269801. ISBN-13: 9788741269801 (978-87-412-6980-1). pp. 20-23. 

Butler, G 2016, Constitutional Limits of the EU's Common Foreign and Security Policy. Ph.D. thesis. 333 pp. 

Butler, G 2016, 'Attacking or Defending? Jurisdiction of the Court of Justice in the EU's Common Foreign and Security Policy' Europarättslig Tidskrift (Swedish European Law Journal), vol 19, no. 4, pp. 671-684. Link: ert.se/Journals/Journal/1051.

Butler, G & Ratcovich, M 2016, 'Operation Sophia in Uncharted Waters: European and International Law Challenges for the EU Naval Mission in the Mediterranean Sea' Nordic Journal of International Law, vol 85, no. 3, pp. 235-259. DOI: 10.1163/15718107-08503003. 

Cited in:

• Opinion of Advocate General Eleanor Sharpston, Case C-670//16, Tsegezab Mengesteab v Federal Republic of Germany, ECLI:EU:C:2017:480, Court of Justice of the European Union (Grand Chamber case).

Butler, G, Jensen, MD & Snaith, H (eds) 2016, 'British Exit from the EU: Legal and Political Implications' Journal of European Public Policy, vol 23, no. 9, pp. 1278-1328.

Butler, G, Jensen, MD & Snaith, H 2016, '‘Slow change may pull us apart’: debating a British exit from the European Union' Journal of European Public Policy, British Exit from the EU: Legal and Political Implications, Butler, G, Jensen, MD & Snaith, H (eds) vol 23, no. 9, pp. 1278-1284. DOI: 10.1080/13501763.2016.1174527. 

Butler, G 2016, 'A new means of dissemination for doctoral research in Danish legal education' Retfaerd (Nordic Journal of Law and Justice), vol 39, no. 1/152, pp. 88-95.

Butler, G 2016, 'The Ultimate Stumbling Block? The Common Foreign and Security Policy, and Accession of the European Union to the European Convention on Human Rights' Dublin University Law Journal, vol 39, no. 1, pp. 229-244. 

Butler, G 2015, 'Pinpointing the Appropriate Legal Basis for External Action' European Journal of Risk Regulation, vol 6, no. 2, pp. 323-328.

Butler, G 2015, 'A Political Decision Disguised as Legal Argument? Opinion 2/13 and European Union Accession to the European Convention on Human Rights' Utrecht Journal of International and European Law, vol 31, no. 81, pp. 104-111. DOI: 10.5334/ujiel.df

Butler, G 2015, 'The Interparliamentary Conference on the CFSP/CSDP: A new forum for the Oireachtas in Irish and EU foreign policy?' Irish Studies in International Affairs, vol 26, pp. 163-186. DOI: 10.3318/isia.2015.26.4

Butler, G 2015, 'Not a “real” common travel area: Pachero v Minister for Justice and Equality' Irish Jurist, vol 54, pp. 155-164.

Butler, G 2015, 'The Road to a Court of Appeal—Part I: History and Constitutional Amendment' Irish Law Times, vol 33, no. 14, pp. 208-211.

Butler, G 2015, 'The Road to a Court of Appeal—Part II: Distinguishing Features and Establishment' Irish Law Times, vol 33, no. 15, pp. 222-226.