Arathorn II is the name of Aragorn’s father in J.R.R. Tolkien’s Middle-earth legendarium.
Arathorn II was the sixteenth chieftain of the Dúnedain of the North. He married Gilraen and became the father of Aragorn, who was born in 2931 of the Third Age. Arathorn was killed by Orcs when Aragorn was only two years old, after which Aragorn was raised in Rivendell under the protection of Elrond.
Arathorn should not be confused with Elendil or Isildur, earlier ancestors in Aragorn’s royal line. Aragorn’s inherited claim to the thrones of Arnor and Gondor ultimately descends through that lineage. The Roman numeral distinguishes Aragorn’s father from an earlier figure named Arathorn in Tolkien’s genealogical material.