1963 Event 2nd session of Ecumenical council, 'Vatican II,' opens in Rome 1962 Event 2nd Vatican Council (21st ecumenical) convened by Pope John XXIII 1869 Event 20th Roman Catholic ecumenical council, Vatican I, opens in Rome 1545 Event Council of Trent (19th ecumenical council) opens 1414 Event Council of Constance (16th ecumenical council) opens 1311 Event Council of Vienne (15th ecumenical council) opens 1274 Event 2nd Council of Lyons (14th ecumenical council) opens 1245 Event 1st Council of Lyons (13th ecumenical council) opens 1215 Event 4th Lateran Council (12th ecumenical council) opens in Rome 1179 Event 3rd Lateran Council (11th ecumenical council) opens in Rome 1139 Event 2nd Lateran Council (10th ecumenical council) opens in Rome 1123 Event 1st Latern Council (9th ecumenical council) opens in Rome 870 Event 8th Ecumenical council ends in Constantinople 869 Event 4th Council of Constantinople (8th ecumenical council) opens 787 Event 2nd Council of Nicaea (7th ecumenical council) opens in Asia Minor 680 Event 3rd Council of Constantinople (6th ecumenical council) opens 553 Event 2nd Council of Constantinople (5th ecumenical council) opens 451 Event Council of Chalcedon (4th ecumenical council) opens 431 Event Council of Ephesus (3rd ecumenical council) opens 325 Event 1st Christian ecumenical council opens at Nicaea, Asia Minor
