Northern Uí Néill

The Northern Uí Néill was any of several dynasties in north-western medieval Ireland that claimed descent from a common ancestor, Niall of the Nine Hostages. Other dynasties in central and eastern Ireland who also claimed descent from Niall are termed the Southern Uí Néill (together they are known as the Uí Néill dynasty). The dynasties of the Northern Uí Néill were the Cenél Conaill and Cenél nEógain, named after the two most powerful sons of Niall: Conall and Eógain.

The Northern Uí Néill's over-kingdom in its earliest days was known as In Fochla and In Tuaiscert, both meaning "the North", and was initially ruled by the Cenél Conaill. After the Cenél nEógain's rise to dominance, it became known as Ailech.