Second Vatican Council
The Second Ecumenical Council of the Vatican, commonly known as the or , addressed relations between the Catholic Church and the modern world. The council, through the Holy See, was formally opened under the pontificate of Pope John XXIII on 11 October 1962 and was closed under Pope Paul VI on the Solemnity of the Immaculate Conception on 8 December 1965.
Pope John Paul II's relations with the Eastern Orthodox Church
With regard to relations with the Serbian Orthodox Church, Pope John Paul II could not escape the controversy of the involvement of Croatian Catholic clergy with the Ustasa regime of World War II. In 1998, he beatified Aloysius Stepinac, the Croatian war-time Archbishop of Zagreb, a move seen negatively by those who believe that he was an active collaborator with the Ustaše fascist regime, which committed genocide against Serbs as well as Jews. On 22 June 2003 he visited Banja Luka in Bosnia and Herzegovina, a city inhabited by many Catholics before the 1992-1995 war, but since then predominantly Orthodox. He held a mass at the Petrićevac monastery, a place of considerable controversy and distress, both during World War II and during the Yugoslav wars.