MYT04 The High King

The Irish High Kings, known as Ard Rí na hÉireann, were a series of historical and legendary figures who claimed to be overlords of Ireland. Their rule, which existed in both mythological and historical contexts, involved periods of both real power and symbolic authority. The concept of a High King dates back to ancient times, with some figures considered legendary, while others are historically documented
here are estimated to have been almost 150 high kings of Tara, the seat of royal power in Ireland for centuries, spanning from prehistory into early historic and medieval times.  
Brian Boru (c 941–1014) was the first king who could truly claim to rule the entire island of Ireland. He was declared Emperor of the Irish in the historic Book of Armagh during his own lifetime, and he has retained a hold on the popular imagination as Ireland's greatest king.
The last High King of Ireland is Rory O'Connor (also known as Ruaidrí Ua Conchobair). He reigned from 1166 to 1198, with his reign coinciding with the arrival of the Anglo-Normans, which effectively ended the High Kingship. While Edward Bruce, a Scottish nobleman, was also proclaimed High King in 1315, his claim was short-lived, and Rory O'Connor is generally recognized as the last native Gaelic High King.