(Ῥωμανὸς ὁ Λακαπηνός), Byzantine emperor from A. D. 919-944, was the son of Theophylactus Abastactus, a brave warrior, who had once saved the life of the emperor Basil.

Romanus served in the imperial fleet, distinguished himself on many occasions, and enjoyed the esteem of his fellow-soldiers on account of his rare bravery. One of his men having been attacked by a lion, Romanus, who was near, rushed to his assistance and killed the monster in single combat. When the young Constantine VII. Porphyrogenitus, ascended the throne, Romanus was high admiral, and commanded the fleet on the Danube in the war with the Bulgarians, but as he suddenly withdrew with his ship and made sail for Constantinople. he was accused of treachery by Leo Phocas. It must, however, be understood that both the accused and the accuser aimed at supreme power, and Romanus left the theatre of the war, probably for the purpose of being within reach of the throne, as well as of the man who wanted to place himself thereon. A civil war was on the point of breaking out, when Romanus, patronised and perhaps loved by the dowager empress, seized upon the chamberlain Constantine, one of the most influential adherents of Phocas, who avenged the captivity of his friend by taking up arms. Romanus, who had been appointed Magnus Hetaeriarcha, or commander in chief of the foreign body-guard of the emperor, worsted Phocas, and in reward was made Caesar in September, and crowned as Augustus and emperor on the 17th December, 919. He had previously given his daughter Helena in marriage to the young emperor Constantine, and shortly after his accession he conferred the rank of Augustus and Augusta upon his son Christopher and his wife Theodora. Romanus was now the legitimate colleague of Constantine VII., over whom he exercised such authority as to cause many plots against his life, and sometimes open rebellions, which he succeeded in quelling.

The following are the principal events of his reign. The great schism of the church, which had lasted ever since the deposition of the patriarch Euthymius and the famous fourth wedlock of the emperor Leo VI., was at last healed, in 920, through the intervention of Pope John X.; and by an edict of Constantine VII. of the same year, a fourth marriage was declared anti-canonical, and made punishable. In 921 another of those interminable wars with the Bulgarians, or perhaps only a fresh and formidable invasion, drew the attention of Romanus towards the Danube, but the Bulgarians saved him the trouble of going so far away from Constantinople by advancing thither with all their force, and ravaging the country. This war became still more formidable when Simeon, the king of the Bulgarians concluded, in 923, an alliance with the Arabs. But we purposely refrain from giving the details of these barbarous wars, presenting little more than an uninterrupted series of bloodshed and devastations without profit to either party. A remarkable interview between Romanus and Simeon, which took place in 926, under the walls of Constantinople, put a temporary end to these troubles. In the previous year the patrician John Radinus worsted and destroyed the fleet of the famous pirate chief Leo, of Tripolis, who had sacked Thessalonica twenty-two years previously. In 927 King Simeon died, after having ruined Bulgaria through his very victories, and was succeeded by his son Peter, who was less warlike, though not less courageous than his father; for he entered the Byzantine territory at the head of a strong army, proposing to the emperor to choose between war and peace, on condition of his giving him his grand-daughter in marriage, a proposition which Romanus the more eagerly accepted, as he wanted all his forces to check the progress of the Arabs. His possessions in Italy also required protection against the petty Lombard princes. In 901 Christopher died, the eldest son of Romanus and husband of Sophia, the daughter of Nicetas magister palatii, who a short time previously had been sent into a convent for a conspiracy against the emperor, Romanus, so wise in many respects, compromised himself extremely in 933, by making his son Theophylactus, a lad of sixteen, patriarch of Constantinople, after first obtaining the approbation of Pope John XI. Theophylactus proved a very miserable prelate. From 934 to 940 the empire enjoyed an almost universal peace, Italy excepted, where the petty warfare with the Lombard princes went on as before. But in 941 Constantinople was in terror at the sudden appearance of a Russian fleet of 10,000 boats, commanded by Prince Ingor, who cast anchor at the very entrance of the Bosporus, and whose troops ravaged the neighbouring country. Romanus, however, equipped in all haste a small number of galleys (15?) lying in the Golden Horn, with which Theophanes boldly attacked the Russians, destroyed a great number of their boats, and compelled Ingor to fly. Theophanes soon afterwards obtained a second victory over the rest of the fleet on the coast of Thrace, and of this formidable armada very little came back to Russia. Ingor died soon afterwards, and in 945 his wife Olga came to Constantinople to receive baptism: she was christened Helena, and is held in the utmost veneration in the Russian church.

Down to this period Constantine Porphyrogenitus, although the legitimate emperor by descent, had only enjoyed the title of his rank, and he now resolved upon having the power also. To this effect he excited the ambition of the two surviving sons of Romanus, Stephanus and Constantine, both Augusti, who in their turn were tired of the autocracy of their aged father. A conspiracy was set on foot, headed by Stephanus, who had the assistance of several energetic and distinguished men. Sure of success, he suddenly seized upon the person of his father, and with secret despatch had him carried to the island of Protea, at the entrance of the Propontis, where Romanus was thrown into a convent and had his head shaved forthwith, as he was thus rendered incompetent to reign (20th of December, 944). The sons of Romanus, however, did not reap the fruits of their treachery, for Constantine VII. was proclaimed sole emperor, after the unnatural children of the deposed emperor had enjoyed the title of co-emperors during the short space of five weeks. They were then arrested and sent to Protea, where a touching interview took place between them and their unfortunate father. Stephanus died nineteen years afterwards in exile, and Constantine survived his captivity only two years, when he was massacred in an attempt at making his escape. Romanus lived a quiet monkish life in his convent, and died a natural death on the 15th of June, 948.