Sacrosanctum Concilium - Vatican II: Constitution On The Sacred Liturgy - Paperbackby Vatican II (Author) Vatican II was one of the most significant events in the life of the modern Church. Between October 1962 and December 1965 the largest ever gathering of Catholic bishops answered the call of Pope John XXIII to let some fresh air into the Church. Completing the work of an earlier Vatican Council that had been cut short, and in a tradition of ecumenical councils dating back to the time of the Apostles, Vatican II laid the