Rómendacil II was born as Minalcar, son of Calmacil and nephew of King Narmacil I, the eighteenth King of Gondor. In TA 1240, he was appointed Regent of Gondor and kept that position throughout the rest of Narmacil I's reign and also during the subsequent reign of his own father, Calmacil.

Minalcar was a man of great valour and when the Easterlings again began to attack the Northmen, he rode with a great army to meet them. In TA 1248 he succeeded in utterly defeating the Easterling armies between Rhovanion and the Sea of Rhûn, along with their camps and settlements. To celebrate his triumph he took the name of Rómendacil, first used by his ancestor King Tarostar (Rómendacil I) and meaning "East-victor".

On his way back he began to fortify the west bank of the River Anduin as far as the inflow of the Limlight and forbade the passing of strangers down the river beyond the Emyn Muil. He also built the Pillars of the Argonath at the entrance to Nen Hithoel. To further strengthen Gondor's alliance with the Northmen and especially with Vidugavia, the self-proclaimed King of Rhovanion, in TA 1250 Rómendacil sent his son Valacar as an ambassador to dwell with the Northern people.

King Narmacil I died childless in TA 1294, and his brother, Calmacil, succeeded to the throne of Gondor. Like his brother, Calmacil left the ruling of his kingdom in the care of Minalcar. When Calmacil died in TA 1304, Minalcar finally succeeded to the throne, becoming Rómendacil II, the nineteenth in the line of the Kings of Gondor.

Rómendacil II ruled as Regent for 64 years (TA 1240 - 1304) and as King of Gondor for 62 years (TA 1304 - 1366) and was succeeded by his son Valacar.
Encyclopedia entry originally written by Nenyia