Romanos I Lakapenos or Lekapenos (c. 870 – 15 June 948), was Byzantine emperor from 920 until his deposition in 944, serving as regent for and senior co-ruler of the young Constantine VII.
 
On 25 March 919, at the head of his fleet, Lekapenos seized the Boukoleon Palace and the reins of government. Initially, he was named magistros and megas hetaireiarches, but he moved swiftly to consolidate his position: in April 919 his daughter Helena was married to Constantine VII, and Lekapenos assumed the new title basileopator. He was named caesar on 24 September 920 and crowned senior emperor on 17 December.
Leo Phokas' supporters surrender to Romanos Lekapenos.
In subsequent years Romanos crowned his own sons co-emperors, Christopher in 921, Stephen and Constantine in 924, although, for the time being, Constantine VII was regarded as first in rank after Romanos himself. It is notable that, as he left Constantine VII untouched, he was called 'the gentle usurper'.[by whom?] Romanos strengthened his position by marrying his daughters to members of the powerful aristocratic families of Argyros and Mouseles, by recalling the deposed patriarch Nicholas Mystikos, and by putting an end to the conflict with the Papacy over the four marriages of Emperor Leo VI.
His early reign saw several conspiracies to topple him, which led to the successive dismissal of his first paradynasteuontes, John the Rhaiktor and John Mystikos. From 925 and until the end of his reign, the post was occupied by the chamberlain Theophanes.
 
Romanos' later reign was marked by the old emperor's heightened interest in divine judgment and his increasing sense of guilt for his role in the usurpation of the throne from Constantine VII. On the death of Christopher, by far his most competent son, in 931, Romanos did not advance his younger sons in precedence over Constantine VII. Fearing that Romanos would allow Constantine VII to succeed him instead of them, his younger sons Stephen and Constantine arrested their father on 20[7] (or  December 944, carried him off to the Princes' Islands and compelled him to become a monk. When they threatened the position of Constantine VII, however, the people of Constantinople revolted, and Stephen and Constantine were likewise stripped of their imperial rank and sent into exile to their father. Romanos died on 15 June 948, and was buried as the other members of his family in the church of Myrelaion.