John I Tzimiskes

John I Tzimiskes became emperor after assassinating his uncle Nikephoros II Phokas. He was a skilled general and continued the military expansion of the Byzantine Empire.

John I led a campaign against the Rus under Sviatoslav I, who had invaded Bulgaria. He defeated the Rus at the Battle of Dorostolon in 971, forcing Sviatoslav to withdraw. This secured Byzantine control over the Balkans.

John I launched a major campaign into Syria, capturing Damascus, Beirut, and other cities. He advanced as far as Jerusalem, but did not capture it. These campaigns extended Byzantine influence in the Levant.

John I Tzimiskes died suddenly, possibly from poison. His death cut short his ambitious campaigns. He was succeeded by Basil II, who would later become known as the 'Bulgar-Slayer'.