The Man who would one day rule as one of Gondor's greatest Kings entered the World in inauspicious circumstances. He was born with the name Minalcar during the reign of Hyarmendacil I, and his father was Calmacil, the younger brother of the King's grandson Narmacil. As such, there seemed little likelihood of his succeeding the throne, but fate would decide otherwise.
Not satisfied with his great victory in the east, Rómendacil set about fortifying the River Anduin. It was he who built the Pillars of the Argonath above Nen Hithoel, as a warning and a marker of Gondor's then northern border. He developed less tangible defences, too, working to cement a bond between Gondor and the Northmen who lived to the east. He went so far to send his son Valacar to live among them, an act from which the evils of the Kin-strife would eventually develop.
Had Narmacil had a son, Minalcar Rómendacil's Regency would have ended with his uncle's death in III 1294. Narmacil died without an heir, however, and his brother, Minalcar's father Calmacil, succeeded instead. Calmacil was King in name only, for he allowed his illustrious son to continue to rule as Regent. On the death of his father ten years later, the man who had actually been ruling Gondor for the previous sixty-four years finally became its true King, under his famous name Rómendacil II.
Rómendacil II ruled as Regent for sixty-four years and as King of Gondor for a further sixty-two years. He was succeeded by his son Valacar.
The date of Rómendacil's birth appears only in The History of Middle-earth volume XII, The Peoples of Middle-earth. It cannot therefore be considered completely reliable.