Arnor is the ancient kingdom destroyed by the Ringwraiths in J.R.R. Tolkien’s Middle-earth.
Arnor was founded by Elendil in the Second Age after the fall of Númenor. It occupied the northern part of the region later called Eriador, while Gondor was established farther south by Elendil’s sons. After Elendil’s death, Arnor was divided among his heirs, weakening the northern kingdom.
The Witch-king of Angmar became Arnor’s principal enemy. His realm of Angmar attacked the successor kingdoms, and the final one, Arthedain, fell in the Third Age. The Ringwraiths were central to this destruction, though war, political division, and plague also contributed to Arnor’s decline. Aragorn is the heir of Isildur and therefore the hereditary claimant to Arnor as well as Gondor. A common mix-up is treating Arnor as another name for Gondor; they were separate kingdoms founded after Númenor’s destruction, with different histories and territories.