Niall of the Nine Hostages is remembered as one of the great early kings of Ireland. Though the details of his life remain uncertain, he is regarded as the ancestor of the Uí Néill dynasties, whose descendants shaped Irish politics for centuries.

Later tradition portrays Niall as a powerful ruler whose influence extended beyond Ireland, including raids on Britain. Stories about the nine hostages reflect the importance of tribute, alliances, and political power in early Gaelic society. His descendants included the ancestors of several prominent royal families in both northern and southern Ireland.