Constantine VIII Porphyrogenitus (Greek: Κωνσταντῖνος Πορφυρογέννητος, Kōnstantinos Porphyrogénnetos; 960 – 11/12 November 1028) was de jure Byzantine emperor from 962 until his death. He was the younger son of Emperor Romanos II and Empress Theophano. He was nominal co-emperor for 63 years (longer than any other), successively with his father; stepfather, Nikephoros II Phokas; uncle, John I Tzimiskes; and brother, Basil II. Basil's death in 1025 left Constantine as the sole emperor.