The heir of Ostoher, who succeeded his father to become Gondor's eighth King. His name had originally been Tarostar, but he changed it to Rómendacil to reflect the heroic events surrounding his succession.
While his father Ostoher was still King, a horde of Easterlings attacked Gondor, the first time such a thing had been known. Ostoher was too old to take command of his own armies, so his son Tarostar took over the kingdom's defence. After two years of fighting, the old King died, and Tarostar inherited the Crown. Another eight years of warfare followed, but in the end Tarostar defeated his enemies and saved Gondor. He took the name Rómendacil in celebration of his triumph; it means 'East-victor'.
Neither Rómendacil's triumph, nor Gondor's peace, were to last indefinitely. Some forty years after his first victory, the Easterlings massed once more, and again attacked the South-kingdom. Rómendacil did not survive the assault, and it was left to his heir Turambar to face the fierce eastern warriors.
Rómendacil ruled Gondor for forty-nine years, and was succeeded by his son Turambar.
The date of Rómendacil's birth appears only in The History of Middle-earth volume 12, The Peoples of Middle-earth. It cannot therefore be considered completely reliable.