Constantine VII Porphyrogenitus (Ancient Greek: Κωνσταντῖνος Πορφυρογέννητος, Kōnstantinos Porphyrogennētos; 17 May 905 – 9 November 959) was the fourth Byzantine emperor of the Macedonian dynasty, reigning from 6 June 913 to 9 November 959. He was the son of Emperor Leo VI and his fourth wife, Zoe Karbonopsina, and the nephew of his predecessor Alexander.
Most of his reign was dominated by co-regents: from 913 until 919 he was under the regency of his mother, while from 920 until 945 he shared the throne with Romanos Lekapenos, whose daughter Helena he married, and his sons. Constantine VII is best known for the Geoponika (τά γεοπονικά), an important agronomic treatise compiled during his reign, and three, perhaps four, books; De Administrando Imperio (bearing in Greek the heading Πρὸς τὸν ἴδιον υἱὸν Ῥωμανόν), De Ceremoniis (Περὶ τῆς Βασιλείου Τάξεως), De Thematibus (Περὶ θεμάτων Άνατολῆς καὶ Δύσεως), and Vita Basilii (Βίος Βασιλείου), though his authorship of the Vita Basilii is not certain.
