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.
Vatican and Eastern Europe (1846–1958)
The Vatican and Eastern Europe (1846–1958) describes the relations from the pontificate of Pope Pius IX (1846–1878) through the pontificate of Pope Pius XII (1939–1958). It includes the relations of the Church State (1846–1870) and the Vatican (1870–1958)
with Russia (1846–1918), Lithuania (1922–1958) and Poland (1918–1958).