Cashel is reputed to be the site of the conversion of the King of Munster by St. Patrick in the 5th century.
The Rock of Cashel was the traditional seat of the kings of Munster for several hundred years prior to the Norman invasion. In 1101, the King of Munster, Muirchertach Ua Briain, donated his fortress on the Rock to the Church. The round tower was constructed c. 1100, Cormac's chapel in 1134 and the Cathedral in 1270.