He was destined to become King of Arnor after his father's death in T.A. 861, but there were constant quarrels between Eärendur's sons. A civil war erupted when Eärendur finally died. Amlaith, however, failed to overcome his two younger brothers, so the Kingdom of Arnor was split into three and Amlaith became the first King of Arthedain. (His brothers founded the kingdoms of Cardolan and Rhudaur).
His reign in Arthedain was largely a peaceful one, although border disputes with the realms of Cardolan and Rhudaur - especially over Amon Sûl and the Weather Hills - never fully ceased. Under his rule the capital was formally removed from Annúminas to Fornost.
Amlaith ruled for eighty-five years, and as succeeded at his death in 946 by his son, Beleg.
Isildur : : : Eärendur | ______________|__________________ | | | | | | AMLAITH Kings of Cardolan Kings of Rhudaur | | Beleg | | Mallor
The name Amlaith is difficult to translate. The first element is am, "up, upwards", but the second element is obscure.
Eärendur of Arnor
|1st King of Arthedain
|The Northern Line and the Heirs of Isildur|
|Kings of Arnor:||Elendil · Isildur · Valandil · Eldacar · Arantar · Tarcil · Tarondor · Valandur · Elendur · Eärendur|
|Kings of Arthedain:||Amlaith · Beleg · Mallor · Celepharn · Celebrindor · Malvegil · Argeleb I · Arveleg I · Araphor · Argeleb II · Arvegil · Arveleg II · Araval · Araphant · Arvedui|
|Chieftains of the Dúnedain:||Aranarth · Arahael · Aranuir · Aravir · Aragorn I · Araglas · Arahad I · Aragost · Aravorn · Arahad II · Arassuil · Arathorn I · Argonui · Arador · Arathorn II · Aragorn II|
|Kings of Arnor:||Elessar · Eldarion|