Halbarad is one of the Dúnedain Rangers and Aragorn’s friend. He and his fellow Rangers catch up with Aragorn on the way to Helm’s Deep, delivering both the royal standard of Gondor and advice from Elrond to follow the Paths of the Dead. His presence, along with the other Rangers’, seems to catalyze Aragorn’s decision to fulfil his destiny as Isildur’s heir and claim the kingship of Gondor.