Gearóid Mór FitzGerald, 8th Earl of Kildare
Gerard Mór FitzGerald, 8th Earl of Kildare, KG (died c. 3 September 1513), known variously as "Garret the Great" (Gearóid Mór) or "The Great Earl" (An Iarla Mór), was Ireland's premier peer. He served as Lord Deputy of Ireland from 1477 to 1494, and from 1496 onwards. His power was so great that he was called "the uncrowned King of Ireland".
More information on the Wikipedia page [1]