Second Ecumenical Council of the Vatican (1962-1965)

The Second Vatican Council, and twenty-first of the Catholic Church, was announced by Pope St. John XXIII on 25 January 1959, the Feast of the Conversion of St. Paul.

Pope John XXIII would convene its first session on 11 October 1962, and, after his death on 3 June 1963, it was continued by Pope St. Paul VI. 

Its last session was formally concluded by Pope Paul VI on 8 December 1965, the Solemnity of the Immaculate Conception of the Blessed Virgin Mary.