During the reign of Eärendur, King of Arnor his sons were in open discord, which erupted into civil war after Eärendur's death in T.A. 861. Amlaith, the true heir to the throne of Arnor, was opposed by his two brothers. Unable to resolve the situation, he was reduced to ruling the region of Arthedain (his brothers created the kingdoms of Cardolan and Rhudaur to the south and east).
