1993 AD - The European Council convened in Copenhagen, Denmark, agreed to the Copenhagen Criteria, requiring religious freedom within all members and prospective members of the European Union

The Copenhagen Criteria are the rules that define whether a country is eligible to join the European Union. The criteria require that a state has the institutions to preserve democratic governance and human rights, has a functioning market economy, and accepts the obligations and intent of the EU.

These membership criteria were laid down at the June 1993 European Council in Copenhagen, Denmark, from which they take their name. Excerpt from the Copenhagen Presidency conclusions:^[2]

Membership requires that candidate country has achieved stability of institutions guaranteeing democracy, the rule of law, human rights, respect for and protection of minorities, the existence of a functioning market economy as well as the capacity to cope with competitive pressure and market forces within the Union. Membership presupposes the candidate's ability to take on the obligations of membership including adherence to the aims of political, economic and monetary union.

Most of these elements have been clarified over the last decade by legislation and other decisions of the European Council, the European Commission and the European Parliament, as well as by the case law of the European Court of Justice and the European Court of Human Rights. However, there are sometimes slightly conflicting interpretations in current member states—some examples of this are given below.

https://en.wikipedia.org/wiki/Copenhagen_criteria

https://en.wikipedia.org/wiki/Copenhagen

https://en.wikipedia.org/wiki/European_Council

https://en.wikipedia.org/wiki/European_Union