Byzantine Emperor Nikephoros II Phokas is assassinated by his wife Theophano and her lover, the later Emperor John I Tzimiskes.

The foundation of Constantinople in 330 AD marks the conventional start of the Eastern Roman Empire, which fell to the Ottoman Empire in 1453 AD. Only the emperors who were recognized as legitimate rulers and exercised sovereign authority are included, to the exclusion of junior co-emperors who never attained the status of sole or senior ruler, as well as of the various usurpers or rebels who claimed the imperial title.

Nikephoros II Phokas, Latinized Nicephorus II Phocas, was Byzantine emperor from 963 to 969. His career, not uniformly successful in matters of statecraft or of war, nonetheless greatly contributed to the resurgence of the Byzantine Empire during the 10th century. In the east, Nikephoros completed the conquest of Cilicia and retook the islands of Crete and Cyprus, opening the path for subsequent Byzantine incursions reaching as far as Upper Mesopotamia and the Levant; these campaigns earned him the sobriquet "pale death of the Saracens".

Theophano was a Greek woman from the region of Laconia, who became Byzantine empress by marriage to emperors Romanos II and Nikephoros II. In 963, between the deaths of Romanos and her marriage to Nikephoros, she was regent for her sons, Basil II and Constantine VIII. Contemporary sources have depicted Theophano as scheming and adulterous, although some modern scholars have called this into question.

John I Tzimiskes was the senior Byzantine emperor from 969 to 976. An intuitive and successful general who married into the influential Skleros family, he strengthened and expanded the Byzantine Empire to include Thrace and Syria by warring with the Rus' under Sviatoslav I and the Fatimids respectively.