Constantine IV vs Tigranes the Great

Constantine IV successfully defended Constantinople against a massive Arab siege that lasted from 674 to 678. The Byzantine victory, aided by the use of Greek fire, forced the Umayyad Caliphate to sue for peace and pay tribute.

Constantine IV continued the reorganization of the Byzantine military into thematic provinces. This system, which combined civil and military authority, proved effective in defending the empire against external threats.

Constantine IV convened the Third Council of Constantinople, which condemned Monothelitism as a heresy. The council restored religious unity between Constantinople and Rome, ending a long-standing theological dispute.

Tigranes conquered the remnants of the Seleucid Empire in Syria and Cilicia, extending his rule to the Mediterranean coast. He assumed the title 'King of Kings' and ruled an empire stretching from the Caspian Sea to the Mediterranean.

Tigranes the Great founded the city of Tigranocerta as his new capital, located in northern Mesopotamia. The city was built with a mixed population of deportees from conquered Greek cities and became a center of Hellenistic culture and trade.

Tigranes was decisively defeated by a Roman army under Lucullus at the Battle of Tigranocerta. The Roman victory led to the capture of the capital and the collapse of Tigranes' empire, reducing Armenia to a client kingdom of Rome.

Tigranes submitted to the Roman general Pompey, who confirmed him as king of Armenia proper but stripped him of all conquered territories. Tigranes paid a large indemnity and became a Roman ally, retaining his throne but losing his empire.