Nicephorus II (Nicephorus Phocas) (nīsĕf´ərəs fō´kəs), c.912–969, Byzantine emperor (963–69). He was a successful general under Constantine VII and Romanus II. On Romanus' death (963) he married the emperor's widow, Theophano, and was proclaimed emperor by his troops. He left the aristocracy its estates and took property from the monasteries. The heavy taxes he imposed to support his military ventures against the Arabs and the Bulgars caused much discontent. His downfall and murder, however, were the result of a palace intrigue between Theophano and her lover, John Tzimisces. Tzimisces succeeded to the throne as John I.