By the 12th century, Ireland was divided politically into a shifting hierarchy of petty kingdoms and over-kingdoms. Power was exercised by the heads of a few regional dynasties vying against each other for supremacy over the whole island. One of these men, King Diarmait Mac Murchada of Leinster was forcibly exiled by the new High King, Ruaidri mac Tairrdelbach Ua Conchobair of the Western kingdom of Connacht.