Tar-Minastir
the eleventh King of Númenor; who aided Gil-galad against Sauron
Names and Lineage
Tar-Minastir was the eleventh King of Númenor, the nephew and successor of the Ruling Queen Tar-Telperiën. He held the Sceptre from S.A. 1731 to 1869, and was the father of Tar-Ciryatan the Shipbuilder, who followed him upon the throne.
The Aid to Gil-galad
In his days the shadow of Sauron lay heavy upon Middle-earth and the Elves, and Gil-galad, High King of the Noldor, was hard pressed. Tar-Minastir sent a great fleet of the Númenóreans and their aid to Gil-galad against Sauron — aid that the annals reckon the last that Númenor gave to the Elves of the West, for after his reign the kings turned away from the friendship of the Eldar.
Significance
Tar-Minastir is the king of the old goodness of Númenor in its strength, the helper of Elves against the Dark, and the last such king: after him the shadow grew within Númenor itself, until the alliance of Elves and Men was not renewed until The Last Alliance at the end of the Second Age.