SilmarienSilmarien - Silmarien was the daughter of Tar-Elendil who would become king of Númenor.  She herself never sat on the throne, but would play a vital role in the history of Middle Earth as the line of Amandil (from whom Isidur and Anarion would come) descended from her.

 

"Meneldur was the son of Tar-Elendil, the fourth King of Númenor.  He was the King's third child, for he had two sisters, named Silmarien and Isilmë.  The elder of these was wedded to Elatan of Andúnië, and their son was Valandil, Lord of Andúnië, from whom came long after the lines of the Kings of Gondor and Arnor in Middle-earth." ~Unfinished Tales (Aldarion and Erendis)

 

In later times when the kings of Númenor became arrogant turned away from the Eldar, the Númenóreans who remained loyal to the Elves and the Valar made their capital in the city of Andúnië.

 

"Highest in honour after the house of the Kings were the Lords of Andúnië; for they were of the line of Elros, being descended from Silmarien, daughter of Tar-Elendil the fourth king of Númenor.  And these lords were loyal to the kings, and revered them; and the Lord of Andúnië was ever among the chief councillors of the Sceptre.  Yet also from the beginning they bore especial love to the Eldar and reverence for the Valar..." ~The Silmarillion (Akallabêth)