Aragorn commonly uses the alias Strider in J.R.R. Tolkien’s The Lord of the Rings.
When Frodo and his companions meet him at the Prancing Pony in Bree, Aragorn is known as Strider. The name reflects his life as a wandering Ranger of the North and helps conceal his royal identity. At first, the hobbits know little about the quiet, weathered traveler.
Aragorn is actually the heir of Isildur and the rightful claimant to the thrones connected with Arnor and Gondor. His identity is revealed gradually as the story develops. The name Strider remains closely linked with the early part of his journey, even after his lineage becomes clear.
Mithrandir is a name for Gandalf, while Elessar is a royal title later associated with Aragorn. Halbarad is another Ranger of the North, not Aragorn’s alias.