He succeeded his father, Tar-Elendil because the rules of succession did not allow women to rule, promoting the principle of agnatic primogeniture. Had the principle of equal primogeniture been followed instead, control of the throne would pass to Silmariën.
He married Almarian and had three children:
- Anardil, son; later known as Aldarion
- Ailinel, daughter -- she would become the mother of Soronto.
- Almiel, daughter
During the rule of Tar-Meneldur contact with the Middle Men of Eriador was reestablished, under guidance of the Elves of Lindon, under Gil-galad. Tar-Meneldur encouraged the seafarers, and allowed his son Aldarion to establish a guild of seafarers, which became one of the most powerful organisations in Númenor. Many voyages along the coasts were made at this time, and the first settlements were made in Middle-earth by Númenórean explorers, although none of them permanent yet. These early settlements were however the later cores of Arnor and Gondor, and the reestablished contact of Númenóreans with their distant kin allowed the Adûnaic tongue to merge with local, far akin languages, eventually leading to the Westron speech. This would in later years prove to be one of the greatest assets to the power of Númenor in Middle-earth.
Near the end of Tar-Meneldur's rule reports came in that evil began to stir in the east of Middle-earth (the first awakenings of Sauron, as was later learned), and Gil-galad requested the aid of Tar-Meneldur. Recognizing his son Aldarion was more aware of the troubles, and was a powerful leader of men, Meneldur resigned in favour of his son, far earlier than was expected.
On the family front Meneldur, together with his wife Almarian, attempted to mediate between his son Aldarion and betrothed Erendis, who had become estranged. For a time they were successful, and Aldarion and Erendis were wed, but Aldarion soon left again for sea. It was during the long absence in Middle-earth, a time during which Aldarion was instructed by Gil-galad, that Erendis left the royal court for her home. By the time Aldarion returned even Meneldur's best attempts could not seal the breach.
Meneldur died in S.A. 942, at the age of 399 years.