The Second Ecumenical Council of the Vatican, or Vatican II, was the twenty-first Ecumenical Council of the Roman Catholic Church. It opened under Pope John XXIII on October 11, 1962 and closed under Pope Paul VI on December 8, 1965. At least four future pontiffs took part in the council's opening session: Cardinal Giovanni Battista Montini, who on succeeding Pope John XXIII took the name of Paul VI; Bishop Albino Luciani, the future Pope John Paul I; Bishop Karol Wojtyła, who became Pope John Paul II; and Father Joseph Ratzinger, present as a theological consultant, who became Pope Benedict XVI.