CELEX:62019CV0001(02): Opinion of the Court (Grand Chamber) of 6 October 2021.#Convention d’Istanbul.#Opinion pursuant to Article 218(11) TFEU – Convention on preventing and combating violence against women and domestic violence (Istanbul Convention) – Signature by the European Union – Draft conclusion by the European Union – Concept of an ‘agreement envisaged’, within the meaning of Article 218(11) TFEU – External competences of the European Union – Substantive legal basis – Article 78(2) TFEU – Article 82(2) TFEU – Article 83(1) TFEU – Article 84 TFEU – Article 336 TFEU – Articles 1 to 4a of Protocol (No 21) on the position of the United Kingdom and Ireland in respect of the area of freedom, security and justice – Partial participation of Ireland in the conclusion of the Istanbul Convention by the European Union – Possibility of splitting the act concluding an international agreement into two separate decisions according to the applicable legal bases – Practice of ‘common accord’ – Compatibility with the TEU and the TFEU.#Case Avis 1/19.