Judgment of the Court (Grand Chamber) of 5 December 2023.#Grand Duchy of Luxembourg and Others v European Commission.#Appeal – State aid – Article 107(1) TFEU – Tax rulings adopted by a Member State – Aid declared incompatible with the internal market – Obligation to recover that aid – Concept of ‘advantage’ – Determination of the reference framework – ‘Normal’ taxation under national law – Review by the Court of Justice of the interpretation and application of national law by the General Court of the European Union – Direct taxation – Strict interpretation – Powers of the European Commission – Obligation to state reasons – Legal classification of the facts – Concept of ‘abuse of law’ – Ex ante assessment by the tax authorities of the Member State concerned – Principle of legal certainty.#Joined Cases C-451/21 P and C-454/21 P.