The Komnenos dynasty came to full power with the coronation of Alexios I Komnenos (pictured) as Byzantine emperor.

The House of Komnenos, Latinized as Comnenus, was a Byzantine Greek noble family who ruled the Byzantine Empire in the 11th and 12th centuries. The first reigning member, Isaac I Komnenos, ruled from 1057 to 1059. The family returned to power under Alexios I Komnenos in 1081 who established their rule for the following 104 years until it ended with Andronikos I Komnenos in 1185. In the 13th century, they founded the Empire of Trebizond, a Byzantine rump state which they ruled from 1204 to 1461. At that time, they were commonly referred to as Grand Komnenoi, a style that was officially adopted and used by George Komnenos and his successors. Through intermarriages with other noble families, notably the Doukas, Angelos, and Palaiologos, the Komnenos name appears among most of the major noble houses of the late Byzantine world.

The Byzantine Empire was ruled by emperors of the Komnenos dynasty for a period of 104 years, from 1081 to about 1185. The Komnenian period comprises the reigns of five emperors, Alexios I, John II, Manuel I, Alexios II and Andronikos I. It was a period of sustained, though ultimately incomplete, restoration of the military, territorial, economic and political position of the Byzantine Empire.

Alexios I Komnenos, 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.