Amlaith of Fornost was the first King of Arthedain (T.A. 861-946). The eldest of the three sons of Eärendur of Arnor, the last King of Arnor, he claimed the choicest portion of his father's domain, for after Eärendur's death Arnor was sundered. Amlaith took Arthedain, leaving Cardolan and Rhudaur to his brothers. Then he moved his capital from the ancient and beautiful city of Annúminas to the fortified summer retreat at Fornost Erain.
Amlaith was generally a noble king, but he was ambitious and could be somewhat insensitive to his people's needs. He supported Arthedain's focus on lore and the magic arts, and maintained the law with an abiding vigor. Yet, he exercised mercy only infrequently, and many of the Arthadan nobles chafed under his firm hand.