The Second Ecumenical Council of the Vatican, commonly known as the Second Vatican Council, or Vatican II, was the 21st 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).
Pope John XXIII called the council because he felt the Church needed "updating" (in Italian: aggiornamento). In order to better connect with people in an increasingly secularized world, some of the Church's practices and teachings needed to be improved and presented in a more understandable and relevant way. Many Council participants were sympathetic to this, while others saw little need for change and resisted. Support for aggiornamento won out over resistance to change, and as a result the sixteen magisterial documents produced by the council proposed significant developments in doctrine and practice: an extensive reform of the liturgy; a renewed theology of the Church, of revelation and of the laity; and new approaches to relations between the Church and the world, to ecumenism, to non-Christian religions, and to religious freedom.
The council had a significant impact on the Church, due to the scope and variety of issues it addressed.
Pope Pius XII's 1943 encyclical Divino afflante spiritu gave a renewed impetus to Catholic Bible studies and encouraged the production of new Bible translations from the original languages. This led to a pastoral attempt to get ordinary Catholics to re-discover the Bible, to read it, to make it a source of their spiritual life. This found a response in very limited circles. By 1960, the movement was still in its infancy.