1055

By place

Byzantine Empire

• January 11 - Emperor Constantine IX dies after a 12½-year reign at Constantinople. He is succeeded by Theodora who is proclaimed by the imperial guard as empress of the Byzantine Empire.

  Europe

• King Ferdinand I begins his campaign against al-Andalus. He conquers Seia from the Christian allies of the Muslim taifas. In a drive to consolidate his southern border in Portugal – Ferdinand re-populates the city of Zamora with some of his Cantabrian subjects.

  England

• October 24 - Ælfgar, earl of Mercia, is outlawed by the witan. In revenge he builds a force and allies himself with the Welsh king Gruffydd ap Llywelyn. After defeating Ralph the Timid, they attack Hereford and raid the church – taking everything of value leaving the building on fire. The rebels also attack Leominster.
• Edward the Confessor gives Tostig Godwinson the important position as earl of Northumbria and the difficult mission of bringing the northern state under control.

  Arabian Empire

• Winter - The Seljuk Turks led by Sultan Tughril capture Baghdad and enter the city in a Roman-styled truimph. Al-Malik al-Rahim, the last Buyid emir in Iraq, is taken prisoner.

  By topic

Art

• Construction on the Liaodi Pagoda in Hebei is completed.

  Religion

• King Andrew I establishes the Benedictine Tihany Abbey. Its foundation charter is the earliest written record extant in the Hungarian language.
• April 13 - Pope Victor II succeeds Leo IX as the 153rd pope of the Catholic Church in Rome.