Arassuil was the eleventh of the Chieftains of the Dúnedain.
Arassuil became the Chieftain of the Dúnedain in 2719 at the death of his father.
During his rule the Orcs of the Misty Mountains became more bold, daring to invade Eriador. The Rangers fought many battles trying to hold them back, but one party of Orcs managed to reach the Shire, where they were fought off by a party of brave Hobbits under Bandobras Bullroarer Took.
Arassuil died in 2784, and was followed by his son Arathorn I.