The Irish High King Rory O'Connor exiled Dermot MacMurrough, the King of Leinster, in 1166. With the help of Anglo-Norman forces, he invaded Ireland in 1169. The Norman forces quickly conquered large swaths of land. The English King Henry II became wary of a rival Norman kingdom in Ireland and visited in 1171 to assert his authority. Soon after he arrived, however, Richard de Clare, or "Strongbow," the leader of the Normans, was killed in battle. The Norman power structure was shaken and the Irish kings began to reclaim some of their land. Henry II rethinks his expansionist policies and takes greater caution with his kingdom, leading to a longer-lasting Angevin Empire.