Constantine VII Porphyrogenitos ("the Purple-born") was the son of Byzantine emperor Leo VI and nephew of Alexander III. He earned his nickname as the legitimate (or more accurately legitimized) son of Leo, as opposed to the others who claimed the throne during his lifetime. He succeeded to the throne at the age of seven in 913, under the regency of the Patriarch Nicholas Mysticus.
Nicholas was forced to make peace with Symeon of the Bulgars, whom he reluctantly recognized as Bulgarian emperor. Because of this, Nicholas was driven out of the regency by Constantine's mother ZoŽ. ZoŽ was no more successful with the Bulgars, and in 919 she was replaced with Romanus Lecapenus, who married his daughter Helena to Constantine. Romanus took power for himself until 944, when he was deposed by his sons, who then finally recognized Constantine as emperor.
In 949 Constantine launched another invasion of Crete, but like his father's attempt to retake the island in 911, this attempt also failed. It also provoked the Arabs to attack Byzantine land in Syria, Armenia, and Italy, but the land in the east was eventually recovered by John Tzimisces. An Arab fleet was also destroyed by Greek fire in 957.
Constantine died in 959 and was succeeded by his son Romanus II. Although he was a satisfactory emperor, Constantine is more well known for his abilities as a writer and scholar. He wrote, or had others write in his name, the works De Ceremoniis (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 in 817. Though these books are not as insightful as Constantine believed them to be, they nevertheless are a useful source of information about Constantine and his reign.
Romanus I (co-emperor)
Romanus II (959)