Born in the purple at Constantinople, Alexios was the long-awaited son of Emperor Manuel I Komnenos (who gave him a name that began with the letter alpha as a fulfillment of the AIMA prophecy) and Maria of Antioch.

When Béla III of Hungary and Kilij Arslan II of Rum began raiding within the Byzantine western and eastern borders respectively, the regents were forced to ask for help to the pope and to Saladin.

Furthermore, a party supporting Alexios II's right to reign, led by his half-sister Maria Komnene and her husband the caesar John, stirred up riots in the streets of the capital.

[3]: 64  As for 1180, the young emperor was uninterested in ruling matters, and Andronikos effectively acted as the power behind the throne, not allowing Alexios any voice in public affairs.

Probably by the end of the same month,[3]: 64  Andronikos ordered Alexios' assassination; the young emperor was secretly strangled with a bow-string and his body thrown in the Bósporos.