But at that time, as we read about in Appendix B of The Return of the King, Strider (who is actually Aragorn II, son of Arathorn II, and later King Elessar) is a young boy living in Rivendell. Aragorn was born in Third Age 2931, and after the death of his father was cared for by Elrond in Rivendell. There he was given the name Estel (Elvish for "hope"). It would not be until Aragorn was 20 (T.A. 2951) that Elrond would reveal to him his lineage and name. After that "Aragorn goes out into the Wild" and gains the name Strider. The Battle of the Five Armies took place in the year T.A. 2941, when Aragorn was only ten years old, ten years before he would become Strider.