Munster - aka Mumhan, Mumu, Muinhneach, Mumhain

Munster in the Early Annals of Ireland

There is some slight evidence for Viking use of the area, at least as a seasonal camp, as the Danes of Limerick made a number of devastating raids in the area in the 9th and 10th centuries, and though the annalistic evidence is ambiguous, seem to have made some of semi-permanent camp along the river or in Lough Corrib. Be that as it may, the earliest known building was erected there in 1124 at the instigation of High King Tairrdelbach mac Ruaidri Ua Conchobair. Both as a naval base and military base Dun Beal Gallimhe offered several advantages. It was surrounded to the north by a number of small islands that, separated from the Dun by large streams and extremely boggy ground, made physical progress difficult and an attack futile. To the south it was bounded by muddy estuary flats and the effects of the tide which made approach from this side just as difficult. The Dun itself was raised at the very end of a thin peninsula of land that could withstand attack by a relatively small number of defenders. Due west was the river, which is one of the fastest-flowing in Europe, and yet almost the only ford on the river. One was to risk a crossing of Lough Corrib, which however can be treacherous at the best of times to an unskilled sailor; second, the unenviable sixty mile slog north to Cong.

From a naval point of view Gallimhe did not make an especially desirable port, lacking a deep harbour. Up to the early 1800s smaller ships docked at the river quay, while larger ones remained at anchor out in the bay for unloading. Yet in the early days of its existence it offered a way into Lough Corrib and its surrounding landmass, from which an invader could strike deep into the heart of Delbhna Tir Dha Locha or Maigh Seola. Conversely it also offered a route out of the latter kingdom and a means to attack its ruler's enemies. Indeed it was used in this capacity both in the 1160s and 1590s. At least some of these factors played a part in subsequent sieges of the settlement. Only much later in its history it would be put to use as the premier merchant port and market of Ireland's west coast. By then it had far outgrown its initial raison d'etre as seen by O Conchobair and de Burgh and become "the City of the Tribes" (Tribes of Galway).

The power of the O'Brien ancestors, lords of Dál gCais, increased greatly in 10th and 11th centuries, to the point they became an important dynasty within all of Munster and culminating with Brian Ború, son of Cendétigh, recognized as the dominant king in Ireland by the turn of the 11th century. Brian's nickname, Ború, comes from Boramha, the name of the village where he was born. Ceann Coradh, now Kincora, was the stronghold of Brian, near the mouth of the Shannon river.

Dalcassian Septs included Ua Briain (O'Brien), Mac Domhnaill (MacDonnell), Ua Gradaigh (O'Grady), Ua hAnrachain (O'Hanrahan), Ua h-Elidhe (O'Healy), Ua Cinneide (O'Kennedy), Mac Con Mara (MacNamara), possibly Ua Cuinn (O'Quinn), Ua hEachtighearna (O'Aherne), and O'Muldoon (Malone) of Ogonelloe in east Co. Clare, among others.