Kevin Egan speaks to Stephen "Of Ireland, the Dalcassians, of hopes, conspiracies, of Arthur Griffith now." His theme is Irish self-rule. The Dalcassians (Dál Cais) were a Gaelic tribe in Munster, with holdings along the River Shannon. They became powerful in the 10th century and produced many kings, including the famous "Brian Boru" (Brian Bóruma in Old Irish, Brian Bóroimhe in modern Irish) of whom Bloom thinks in Ithaca. Until independence in 1922, Brian was the closest that Ireland got to unified native rule.
Brian's older brother Mahon (Mathgamain) became the first King of Munster from the Dalcassian line. Brian himself, after waging war brilliantly in Munster, Leinster, and Connacht, and being acknowledged as the ruler of Ireland's Southern Half (Munster and Leinster), challenged the High King Máel Sechnaill in his home province of Meath. Máel Sechnaill surrendered the title of High King to Brian in 1002.
But the title had seldom if ever been matched by actual control of the entire island, which had hundreds of kings. Brian spent the next decade fighting against the powerful Uí Néill kings in Ulster to make his claim meaningful. By 1011, all the regional powers in Ireland recognized his supremacy, but the fabric began unraveling almost as soon as it was woven. Máel Mórda mac Murchada of Leinster defied the High King in 1012 and fought him for the next two years. Having failed to obtain support from any of the rulers that Brian had dominated in Ulster and Connaught, Máel Mórda turned to Vikings in the Orkney Islands and the Isle of Man, and Hiberno-Norse fighters from the Kingdom of Dublin, to bolster his forces. In April 1014 the two armies met in a furious day-long battle at Clontarf, just north of Dublin on the coast. Brian's forces prevailed, but he was killed in the fighting.
At some point in the 12th century, a work called Cogadh Gaedhil re Gallaibh (The War of the Irish with the Foreigners), possibly commissioned by Brian's great-grandson, cast Brian's victory at Clontarf as a decisive national victory over Norse occupiers. This work succeeded in making Brian a mythic national hero for later ages. But Brian had Norse fighters in his army just as Máel Mórda did, and the Vikings were not really an occupying force. Like many other invaders of Ireland, they had intermarried with natives and adopted local customs (including Christianity) over the course of several generations and hardly consituted an independent population, much less a ruling class.
After Brian, the Dalcassians shrank back to their traditional holdings along the banks of the River Shannon in north Munster, in the Kingdom of Thomond. The descendants of Strongbow attempted to take Thomond in the 13th century, but the Dalcassians fought them off. In the 16th century they submitted to the English King Henry VIII, and their territory north of the Shannon was renamed County Clare. Cyclops twice makes mention of Thomond, once geographically ("from the streamy vales of Thomond, from the M'Gillicuddy's reeks the inaccessible and lordly Shannon the unfathomable") and once politically ("none of your Henry Tudor's harps, no, the oldest flag afloat, the flag of the province of Desmond and Thomond, three crowns on a blue field, the three sons of Milesius"). From 1177 onward the English had adopted the three crowns on a blue field as the standard of the Lord of Ireland (the title of the English king in Ireland). But in 1541 Henry VIII proclaimed himself King of Ireland and adopted the Leinster symbol of the harp.