Centuries of war, including that perpetuated by the power-hungry Vikings, led up to the Norman invasion of Ireland (1169 AD). Irish kings were preoccupied with their own dynastic battles, notably the reign and murder of the high king Brian Boru (ca. 941– 1014). Rome waged a campaign to stamp out corrupt practices within the Celtic Church. After 150 years of rivalry among various factions seeking control of Ireland came the arrival of England's King Henry II in 1171 AD, a great historical and social watershed as the English throne claimed supremacy over Ireland and the Irish – its repercussions continue today.