WHITE, Rev. P. History of Clare and the Dalcassian Clans of Tipperary, Limerick, and Galway. With an ancient and a modern map.

Dublin: Gill, 1893. Octavo. First edition. pp. xvi, 398. Modern green cloth, lettered in gilt, original spine laid on. A good copy. The Dalcassians were a Gaelic tribe, generally accepted by contemporary scholarship as being a branch of the Déisi Muman, who became a powerful grouping in Munster during the tenth century. Their genealogies claimed descent from Cormac Cas, who is said to have lived in the third century.
Brian Bóruma is perhaps the best known king from the dynasty and was responsible to a significant degree for carving out their fortunes. The family had built a powerbase on the banks of the River Shannon and Brian’s brother Mahon became their first King of Munster, taking the throne from the rival Eóganachta. This influence was greatly extended under Brian who became High King of Ireland, following a series of conflicts with Norse and other Irish tribes, before dying famously at the Battle of Clontarf in 1014. Following this the Dál gCais provided three more High Kings of Ireland; Donagh O’Brien, Turlough O’Brien and Murtagh O’Brien; but lost out to the longer established dynasties.
From the 12th-16th centuries, the Dál gCais contented themselves with being reduced to the Kingdom of Thomond. They attempted to claim the Kingdom of Desmond for a time, but ultimately the MacCarthys held it. The Kennedys also held the Kingdom of Ormond for a time. Some of the better known septs included O’Brien, MacNamara, O’Grady, Kennedy, MacMahon and Clancy. During the 13th century Richard Strongbow’s relatives the Norman de Clares attempted to take Thomond, but the Dál gCais held firm.

[Cat 160]