The second son of Elendil, and the younger brother to Isildur. With his father and brother he escaped the drowning of Numenor, and landed safely with Isildur at the mouth of the Anduin in S.A. 3319. Isildur and Anarion sailed up the river till they reached Osgiliath, and there they established the kingdom of Gondor in S.A. 3320.
The brothers divided the kingdom between them, and while Isildur went on to make Minas Ithil his home, Anarion settled in Osgiliath. The brothers placed a Palantír in Minas Anor, Minas Ithil, Orthanc and Osgiliath.
When Sauron attacked Gondor in S.A. 3429, Isildur fled from Minas Ithil, and sailed up the river Anduin to Arnor, the kingdom of Elendil. Meanwhile Anarion valiantly withstood the attacks of Sauron in Osgiliath. In S.A. 3434 Anarion marched out from Osgiliath, leaving his son Meneldil in command of Gondor, to join The Last Alliance of Elves and Men at Dagorlad where the first battles of the Alliance took place.
Anarion was slain by a stone-slinger in S.A. 3440 during the seven years of siege to Barad-Dûr.
It is also said that Anarion's son Meneldil was brother to three brothers, and three sisters, but they all stand unnamed.