21. The Second Vatican Council – 1962-1965 A.D.

The Second Ecumenical Council of the Vatican, commonly known as the Second Vatican Council or Vatican II, was the 21st and most recent ecumenical council of the Catholic Church. The council met in Saint Peter's Basilica in Vatican City for four periods (or sessions), each lasting between 8 and 12 weeks, in the autumn of each of the four years 1962 to 1965. Preparation for the council took three years, from the summer of 1959 to the autumn of 1962. The council was opened on 11 October 1962 by John XXIII (pope during the preparation and the first session), and was closed on 8 December 1965 by Paul VI (pope during the last three sessions, after the death of John XXIII on 3 June 1963).