What is the name of the kingdom Aragorn becomes king of?

Aragorn becomes king of Gondor. After Sauron’s defeat, he is crowned King Elessar and begins the restored united kingdom’s Fourth Age.

Aragorn’s claim comes through his ancestor Isildur, who founded the royal line of Gondor and Arnor. Although Aragorn is raised in secret as a Ranger, he is the rightful heir to the throne. His identity is gradually revealed during the events of The Lord of the Rings.

The answer is sometimes confused with Arnor, the northern kingdom also connected to Aragorn’s ancestry. Aragorn eventually becomes king of both Gondor and the reunited Arnor, but Gondor is the kingdom most directly associated with his coronation and rule. Rohan is a separate neighbouring kingdom, while Mordor is Sauron’s domain, not a human monarchy.