Pope Paul VI promulgates Nostra aetate, by which the Roman Catholic Church officially recognizes the legitimacy of non-Christian faiths.

Pope Paul VI was head of the Catholic Church and sovereign of the Vatican City State from 21 June 1963 until his death on 6 August 1978. Succeeding John XXIII, he continued the Second Vatican Council, which he closed in 1965, implementing its numerous reforms. He fostered improved ecumenical relations with Eastern Orthodox and Protestant churches, which resulted in many historic meetings and agreements. In January 1964, he flew to Jordan, the first time a reigning pontiff had left Italy in more than a century.

Nostra aetate, or the Declaration on the Relation of the Church with Non-Christian Religions, is an official declaration of the Second Vatican Council, an ecumenical council of the Catholic Church. It was promulgated on 28 October 1965 by Pope Paul VI. Its name comes from its incipit, the first few words of its opening sentence, as is tradition. It passed the Council by a vote of 2,221 to 88 of the assembled bishops.

The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institutions and has played a prominent role in the history and development of Western civilization. The Church consists of 24 sui iuris (autonomous) churches, including the Latin Church and 23 Eastern Catholic Churches, which comprise almost 3,500 dioceses and eparchies around the world, each overseen by one or more bishops. The pope, who is the bishop of Rome, is the chief pastor of the church.