Hallacar was of the line of Elros Tar-Minyatur descended through five generations from Vardamir.

After a time he was able to convince Tar-Ancalimë, the first of the Ruling Queens of Númenor, to marry him. He may have married out of love, but it seems pretty clear that Ancalimë married to keep her cousin Soronto from claiming the throne.

Hallacar and Ancalimë had one son who would go on to become the eighth of the Kings of Númenor, Tar-Anárion. After the birth of Anárion, the couple separated and there was strife between them.