Cais, Dál and Boru, Brian

The origins of the Dál Cais, a dynasty of early medieval Ireland, are found in east Limerick, but around the start of the eighth century they were forced to expand into County Clare. They forged alliances with Cormac Cas, who was descended from the Eóganacht, a loose grouping of people who provided many early kings of Munster, and thus attempted to claim a major interest in the kingship of Cashel. From the tenth to the twelfth centuries, just as the fortunes of the Eóganacht declined, the Dál Cais dominated the province of Munster, initially under the leadership of Cenétig mac Lorcáin, and then under his sons Mathgamhain and Brian Boru.

Brian Boru, arguably the most famous king of this dynasty, succeeded to the kingship on the violent death of his brother Mathgamhain in 976. He spent the first part of his reign attempting to consolidate his power over Munster, but when he tried to expand the area of his control into Leinster, he came up against Maél Sechnaill II, then the high king of Ireland. They made a truce in 997, and as a result were able to join together and defeat the Dublin Hiberno-Norse at the battle of Glenn Máma in 999. Brian was the first ruler not from the Uí Néill who made a claim for the high kingship of Ireland, and he was finally acknowledged as such by Máel Sechnaill II in 1002. From the security of his base in the southern part of the country Brian Boru fought several campaigns against the leading dynasties of the northern half of the island. He was slain at the battle of Clontarf in 1014, but not before his army had routed the forces of Leinster and their Norse allies. It was his strategic skills, especially the construction of defensive fortifications and his employment of naval power, that made him such an effective military leader. His astute political sense and the appointment of many of his relations to major offices within the church of Munster ensured the close control of the church. Therefore, it is hardly surprising that, following Clontarf, he was buried in Armagh, the primatial capital, and he was also given the title Imperator Scotorum (emperor of the Irish) in the Book of Armagh, a ninth-century gospel book.

Despite the death of Brian, the Dál Cais were able to maintain their control of Munster through other strong leaders, some of whom were descendants of Brian Boru, right up until the early part of the twelfth century. But after the death of Muirchertach O'Brien in 1119, the O'Briens, as they came to be called in memory of Brian Boru, had a more limited role in the politics of Munster.

SEE ALSO Clontarf, Battle of; Norse Settlement; O'Connors of Connacht; Uí Néill High Kings

Bibliography

Byrne, Francis John. Irish Kings and High-Kings. 1973.

Ryan, John. "Brian Bóruma, King of Ireland." In North Munster Studies, edited by Étienne Rynne. 1967.

Terry Barry