"Constantine VII Porphyrogennetos or Porphyrogenitus (Greek: Κωνσταντῖνος Ζ΄ Πορφυρογέννητος, romanized: Kōnstantinos VII Porphyrogennētos; 17–18 May 905 – 9 November 959) was the fourth Emperor of the Macedonian dynasty of the Byzantine Empire, reigning from 913 to 959. He was the son of the emperor Leo VI and his fourth wife, Zoe Karbonopsina, and the nephew of his predecessor, the emperor 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 his 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)." - (en.wikipedia.org 12.12.2019)
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