1054

align="center" colspan=2 | Years:
1051 1052 1053 - 1054 - 1055 1056 1057

align="center" colspan=2 | Decades:
1020s 1030s 1040s - 1050s - 1060s 1070s 1080s

align="center" | Centuries:
10th century - 11th century - 12th century

Events

Cardinal Humbertus, a representative of Pope Leo IX, and Michael Cerularius, Patriarch of Constantinople, decree each other's excommunication. Some historians look to this act as initiating the Great Schism between the Roman Catholic and Orthodox Christian Churches. To this day each claims to be the One Holy Catholic and Apostolic Church and each denies the other's right to that name. However, at the time of the excommunication, the Pope was dead; therefore, Cardinal Humbertus' act had no legal force. Moreover, individuals were excommunicated, not entire Churches.
Malcolm Canmore begins his campaign for the throne of Scotland.
July 4 - A supernova is recorded by the Chinese and possibly Native Americans near the star ζ Tauri. For several months it remains bright enough to be seen during the day. Its remnants form the Crab Nebula.
July 27 - King Macbeth of Scotland's troops defeated in Dunsinane Hill. Macbeth himself escapes.