Aragorn is the only member of the Fellowship to be crowned King of Gondor.
Aragorn is crowned King Elessar after the defeat of Sauron and the destruction of the One Ring. He is the heir of Isildur and the descendant of the kings of Númenor, making his claim to Gondor’s throne part of the central political history of The Lord of the Rings.
Before becoming king, Aragorn is introduced as Strider, a Ranger of the North. His identity and responsibilities are gradually revealed as the Fellowship’s journey develops. He fights alongside the other members of the Fellowship but also leads armies and accepts the burden of restoring the kingdoms of Gondor and Arnor.
Boromir is a son of Gondor’s ruling Steward, not its king, while Gandalf, Legolas, and Gimli hold different roles. Aragorn’s coronation therefore completes both his personal arc and the restoration of a royal line.