Alexios I Komnenos

Alexios I Komnenos (, – 15 August 1118), Latinized as Alexius I Comnenus, was Byzantine emperor from 1081 to 1118. After usurping the throne he was faced with a collapsing empire and constant warfare throughout his reign. Alexios was able to curb the Byzantine decline and begin the military, financial, and territorial recovery known as the Komnenian restoration. His appeals to Western Europe for help against the Seljuk Turks were the catalyst that sparked the First Crusade.

Although he was not the first emperor of the Komnenian dynasty, it was during his reign that the Komnenos family came to full power and initiated a hereditary succession to the throne. The son of John Komnenos and a nephew of Isaac I Komnenos, Alexios served with distinction under three Byzantine emperors. In 1081, he led a rebellion against Emperor Nikephoros III Botaneiates and took the throne for himself.

He immediately faced an invasion of the western Balkans by the Normans under Robert Guiscard and his son Bohemond. Despite initial defeats, Alexios secured an alliance with Holy Roman Emperor Henry IV and drove back the Normans, recovering most of Byzantine losses by 1085. In 1091, he achieved a decisive victory over the Pechenegs at the Battle of Levounion in Thrace with the help of Cuman allies. Later in the 1090s, Alexios directed his attention towards Asia Minor, most of which had fallen to the Seljuk Turks.

Desiring western support, he took reconciliatory measures towards the Papacy, and in 1095 his envoys made a formal appeal to Pope Urban II at the Council of Piacenza.