He was the eldest son of Gondorian Valacar and Vidumavi daughter of the King of Rhovanion. Being born as Vinitharya while in the land of his mother, when Valacar was asked to return to Gondor he was given the new name Eldacar.
Even when he showed no signs of aging any differently to the Dunedain, the rebels lead by distant relative Castamir laid siege to Osgiliath.
This army was enhanced by the people of Calenardhon, Anorien and Ithilien.
The largest battle happened at the Crossings of Erui. Eldacar took revenge by eliminating Castamir during battle.
After the remnants of the rebellion fled to Umbar, Gondor was left in peace. Eldacar ruled until his 235th year, proving that his mother’s lineage had no effect on his lifespan. He was succeeded by his younger son Aldamir.
“To the lineage of Gondor he added the fearless spirit of the Northmen. He was handsome and valiant, and showed no sign of ageing more swiftly“Appendix A