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.

[2][3] The epithet porphyrogenitus alludes to the Purple chamber of the imperial palace, decorated with porphyry, where legitimate children of reigning emperors were normally born.

[9] Following Alexander's death (6 June),[10] the new and shaky regime survived the attempted usurpation of Constantine Doukas,[11] and Patriarch Nicholas Mystikos quickly assumed a dominant position among the regents.

[12] Patriarch Nicholas was presently forced to make peace with Tsar Simeon of Bulgaria, whom he reluctantly recognized as Bulgarian emperor.

Constantine had active diplomatic relationships with foreign courts, including those of the caliph of Cordoba Abd ar-Rahman III and of Otto I, Holy Roman Emperor.

[2] He wrote, or had commissioned, the works Geoponika ("On Agriculture", in Greek Τὰ γεωπονικά), a compilation of agronomic works from earlier Greek and Punic texts that are otherwise lost; De Ceremoniis ("On Ceremonies", in Greek, Περὶ τῆς βασιλείου τάξεως), 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", bearing in Greek the heading Πρὸς τὸν ἴδιον ὑιὸν Ρωμανόν),[1] giving advice on running the Empire internally and on fighting external enemies; a history of the Empire covering events following the death of the chronographer Theophanes the Confessor in 817; and Excerpta Historica ("Excerpts from the Histories"), a collection of excerpts from ancient historians (many of whose works are now lost) in four volumes (1.

In The Manuscript Tradition of Polybius, John Michael Moore (CUP, 1965) provides a useful summary of the commission by Porphyrogenitus of the Constantine Excerpts: He felt that the historical studies were being seriously neglected, mainly because of the bulk of the histories.

He therefore decided that a selection under fifty-three titles should be made from all the important historians extant in Constantinople; thus he hoped to assemble in a more manageable compass the most valuable parts of each author.

[28] Also amongst his historical works is a history eulogizing the reign and achievements of his grandfather, Basil I (Vita Basilii, Βίος Βασιλείου).

In his book, A Short History of Byzantium, John Julius Norwich refers to Constantine VII as "The Scholar Emperor".

[29] Norwich describes Constantine: 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.

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.