As such, the European Council had already existed before it gained the status as an institution of the European Union with the entering into force of the Treaty of Lisbon, but even after it had been mentioned in the treaties (since the Single European Act) it could only take political decisions, not formal legal acts. However, when necessary, the Heads of State or Government could also meet as the Council of Ministers and take formal decisions in that role. Sometimes, this was even compulsory, e.g. Article 214(2) of the Treaty establishing the European Community provided (before it was amended by the Treaty of Lisbon) that ‘the Council, meeting "in the composition of Heads of State or Government" and acting by a qualified majority, shall nominate the person it intends to appoint as President of the Commission’ (emphasis added); the same rule applied in some monetary policy provisions introduced by the Maastricht Treaty (e.g. Article 109j TEC). In that case, what was politically part of a European Council meeting was legally a meeting of the Council of Ministers. When the European Council, already introduced into the treaties by the Single European Act, became an institution by virtue of the Treaty of Lisbon, this was no longer necessary, and the "Council the European Union meeting in the composition of the Heads of State or Government", was replaced in these instances by the European Council now taking formal legally binding decisions in these cases (Article 15 of the Treaty on European Union).