The Byzantine emperor Basil II (ca. 958-1025) ruled from 963 to 1025 and was called Bulgaroctonus (Bulgar-Slayer). He was the last and greatest of the emperors who brought Byzantium to its military zenith.

The elder son of Emperor Romanus II, Basil and his younger brother, Constantine, succeeded in title as children upon their father's death in 963. Their position was exploited by two successive military usurpers, Nicephorus Phocas (963-969) and John I Tzimisces (969-976). Upon John's death, while Constantine remained in the background, Basil attempted to rule but became dependent upon his great-uncle, the eunuch Basil the Chamberlain. A cunning politician of long experience, the chamberlain helped Basil face the challenges of two more would-be usurpers, the aristocrats Bardas Sclerus and Bardas Phocas. Amid these struggles the chamberlain's tutelage became intolerable, and Basil drove him from office.

The rebellions of the two Bardases eventually drove Basil to seek military help from...