Isaac Komnenos (brother of Alexios I)

Isaac Komnenos
Sebastokrator of the Byzantine Empire
Seal of Isaac as protoproedros and domestikos ton scholon of the East in c. 1073, showing the military saint St. Theodore
Born	c. 1050 Constantinople (modern-day Istanbul, Turkey)
Died	1102/1104 Constantinople
Spouse	Irene of Alania
Issue	John, Alexios, Constantine, Adrianos, Sophia, unknown daughter
House	Komnenos
Father	John Komnenos
Mother	Anna Dalassene
Religion	Eastern Orthodox Church

Isaac Komnenos or Comnenus (Greek: Ἰσαάκιος Κομνηνός, Isaakios Komnēnos; c. 1050 – 1102/1104^[1]) was a notable Byzantine aristocrat and military commander in the 1070s. Isaac played a major role in the rise to the throne of his younger brother, the Byzantine Emperor Alexios I Komnenos (r. 1081–1118), and remained a leading figure in his brother's administration until his death.

Isaac was born to the highest aristocracy of mid-11th century Byzantium, a position reinforced through marriage ties to the imperial Doukas dynasty. Well educated and brave, in 1073–1078 Isaac occupied two of the highest military positions in the Byzantine Empire, as Domestic of the Schools and doux of Antioch. His military record against the Seljuk Turks was not particularly distinguished, but on his return to Constantinople in 1078 he gained the favour of Emperor Nikephoros III Botaneiates, and of Empress Maria of Alania. Isaac and Alexios used imperial favour to further their own designs on the throne, launching a revolt in early 1081 that saw Alexios crowned emperor. As a reward, Alexios created the title of sebastokrator for Isaac, which put him almost on par with the emperor. During Alexios' reign and until his death, Isaac played an important role in domestic affairs in matters of public order and justice, being called to examine several cases of conspiracy or heretical teachings.