Niall of The Nine Hostages

Niall Noígíallach (, Old Irish "having nine hostages"), or in English, Niall of the Nine Hostages, son of Eochaid Mugmedón, was an Irish king, the eponymous ancestor of the Uí Néill kindred who dominated Ireland from the 6th to the 10th century. The rise of the Uí Néill dynasties and their conquests in Ulster and Leinster are not reliably recorded but have been the subject of considerable study and attempts to reconstruct them.

Although generally supposed to be a historical personage, very little can confidently be said of Niall's life. The sources for the details of Niall's life are genealogies of historical kings, the "Roll of Kings" section of the Lebor Gabála Érenn, Irish annals such as the Annals of the Four Masters, chronicles such as Geoffrey Keating's Foras Feasa ar Éirinn, and legendary tales like "The Adventure of the Sons of Eochaid Mugmedon" and "The Death of Niall of the Nine Hostages". These sources date from long after Niall's time and their value as history is limited at best.

Niall is placed in the traditional list of High Kings of Ireland. His reign is dated to the late 4th and early 5th centuries. The Annals of the Four Masters dates his accession to 378 and death to 405. The chronology of Keating's Foras Feasa ar Éirinn broadly agrees, dating his reign from 368-395, and associating his raiding activities in Britain with the kidnapping of Saint Patrick (ca. 390-461). However, the traditional roll of kings and its chronology is now recognised as artificial. The High Kingship did not become a reality until the 9th century, and Niall's legendary status has been inflated in line with the political importance of the dynasty he founded. Based on Uí Néill genealogies and the dates given for his supposed sons and grandsons, modern historians believe he is likely to have lived some 50 years later than the traditional dates, dying circa 450.