850 First Viking - Irish alliance.
1002 Brian Boru becomes High King of Ireland.
1014 Danish command of the east coast broken at Battle of Clontarf, led by Brian Boru. Boru is killed in the battle.
Since the 8th Century, bands of Vikings have been attacking the coast of Ireland and travelling upriver in their longboats to raid the inland monasteries. They attacked these monastic settlements as they where the focal points of economic activity in the country. The monks built round towers to serve as lookouts and safe storage for their precious documents and treasures. IN time, the Vikings established more permanent bases at the mouth of rivers such as the Liffey, the Lee and the Shannon and from there were able to launch more extensive campaigns across the country. But Brian Brou, having built up a dynasty in Munster, had ambition to become King of Ireland. In1014, he won major victory at Clontarf against the King of Leinster who had sought the assistance of the Vikings. Although he himself was killed in battle, his victory led to the decline of the Viking influence.
The Rock of Cashel has been associated with Christianity since the time of St. Patrick. Cashel has also been the seat of the Kings of Munster. The oldest surviving building on the Rock is Cormacís chapel, which was built in 1011 by Cormac Mac Carthaig, King of Munster, in a style influenced by German architecture. It is Irelandís first Romanesque church and introduced many innovations such as exotic stone roof, stone Ė carving decorations and a frescoed interior. Although Ireland adopted Roman Christianity, it was largely self-governing, and very lax in the Roman rules especially regarding priestly celibacy and marriage. In 1111 there was a national synod near Cashel, which divided the country into 24 dioceses to replace the old monastic structure. At a later synod Cashel was to become one of four archdioceses.
First Cistercian monastery built in Ireland, at Mellifont, Louth.
1142 First Cistercian monastery built in Ireland, at Mellifont, Louth.