See study by A. Toynbee (1973).
Constantine VII Porphyrogennetos or Porphyrogenitus, "the Purple-born" (Greek: Κωνσταντίνος Ζ΄ Πορφυρογέννητος, Kōnstantinos VII Porphyrogennētos), (September 2, 905 – November 9, 959) was the son of the Byzantine emperor Leo VI and his fourth wife Zoe Karbonopsina. He was also the nephew of the Emperor Alexander. He is famous for his two descriptive books, De Administrando Imperio and De Ceremoniis.
His nickname alludes to the Purple Room of the imperial palace, decorated with the stone porphyry, where legitimate children of reigning emperors were normally born. Constantine was also born in this room, although his mother Zoe had not been married to Leo at that time. Nevertheless, the epithet allowed him to underline his position as the legitimized son, as opposed to all others who claimed the throne during his lifetime. Sons born to a reigning Emperor held precedence in the Byzantine line of ascension over elder sons not born "in the purple".
Zoe was no more successful with the Bulgarians, by whom her main supporter, the general Leo Phokas, was defeated in 917, and in 919 she was replaced by the admiral Romanos Lekapenos, who married his daughter Helena Lekapene to Constantine. Romanos used his position to advance to the ranks of basileopatōr in May 919, kaisar (Caesar) in September 920, and finally co-emperor in December of the same year. Thus, just short of reaching nominal majority, Constantine was again eclipsed by a senior emperor.
Constantine's youth had been a sad one for his unpleasant appearance, his taciturn nature and his relegation at the third level of succession behind the eldest son of Romanos I Lekapenos. Nevertheless, he was a very intelligent young man with a large range of interests, and dedicated those years to study the court's ceremonial.
Romanos kept power for himself and maintained it until 944, when he was deposed by his sons Stephen and Constantine. With the help of his wife, Constantine VII succeeded in removing his brothers-in-law and on January 27, 945, Constantine VII was once again sole emperor at the age of 39, after a life spent in the shadow. Several months later, Constantine VII crowned his own son Romanos II co-emperor. Having never exercised executive authority, Constantine remained primarily devoted to his scholarly pursuits and relegated his authority to bureaucrats and generals, as well as his energetic wife Helena Lekapene.
In 949 Constantine launched a new fleet of 100 ships (20 dromons, 64 chelandia, and 10 galleys) against the Arab corsairs hiding in Crete, but like his father's attempt to retake the island in 911, this attempt also failed. On the Eastern frontier things went better, even if with alternate success: in 949 the Byzantines conquered Germanicea, repeatedly defeated the enemy armies and in 952 crossed the upper Euphrates. But in 953 the Arab amir Saif ad-Dawla retook Germanicea and entered the imperial territory. The land in the east was eventually recovered by Nikephoros Phokas, who conquered Hadath, in northern Syria, in 958, and by the Armenian general John Tzimiskes, who one year later captured Samosata, in northern Mesopotamia. An Arab fleet was also destroyed by Greek fire in 957. Constantine's efforts to retake themes lost to the Arabs were the first such efforts to have any real success.
Constantine had intense diplomatic relationships with foreign courts, including the caliph of Cordoba Abd ar-Rahman III and Otto I, King of Germany. In the autumn of 957 Constantine was visited by Olga, princess of the Kievan Rus'. The reasons for this voyage have never been clarified: in any case, she was baptised with the name Helena, and began to convert her people to Christianity.
Constantine VII was renowned for his abilities as a writer and scholar. He wrote, or had commissioned, the works De cerimoniis aulae byzantinae ("On Ceremonies"), describing the kinds of court ceremonies also described later in a more negative light by Liutprand of Cremona; De Administrando Imperio ("On the Administration of the Empire"), giving advice on running the empire internally and also how to fight external enemies; and a history of the Empire covering events following the death of the chronographer Theophanes the Confessor in 817. Amongst his historical works was a history eulogising the reign and achievements of his grandfather, Basil I. These books are insightful and are of immense interest to the historian, sociologist and anthropologist as a most useful source of information about nations neighbouring with Byzantium. They also offer a fine insight into the Emperor himself.
In his book, A Short History of Byzantium, John Julius Norwich refers to Constantine VII as "The Scholar Emperor" (180). Norwich states, “He was, we are told, a passionate collector--not only of books and manuscripts but works of art of every kind; more remarkable still for a man of his class, he seems to have been an excellent painter. He was the most generous of patrons--to writers and scholars, artists and craftsmen. Finally, he was an excellent Emperor: a competent, conscientious and hard-working administrator and an inspired picker of men, whose appointments to military, naval, ecclesiastical, civil and academic posts were both imaginative and successful. He did much to develop higher education and took a special interest in the administration of justice (181). In 947, Constantine VII ordered the immediate restitution, without compensation, of all peasant lands, thus, by the end of [his] reign, the condition of the landed peasantry—which formed the foundation of the whole economic and military strength of the Empire—was better off than it had been for a century" (182-3).