The present county formed from a very early period a native principality, designated Tuath-Mumhan, or Thomond, signifying "North Munster;" and contained the six cantreds of Hy Lochlean, Corcumruadh, Ibh Caisin, Hy Garman, Clan Cuilean, and Dal Gaes. In Hy Lochlean, or Bhurrin, the barony of Burren, the O'Loghlins or O'Laghlins were chiefs; in Corcumruadh, the modern Corcomroe, the O'Garbhs (although that portion is stated by Ware to have been occupied by the septs of O'Connor and O'Loghlin); in Ibh Caisin, the present Ibricklane, the Cumhead-mor O'Briens, this being the hereditary patrimony of the O'Briens or O'Bricheans; in Hy Garman, the modern Moyarta, the O'Briens Arta; and in Clan Cuilean, the present Cloberlaw, the Mac Namaras; Dal Gaes comprised the more extensive districts included in the baronies of Inchiquin, Bunratty, and Tulla, forming the entire eastern half of the present county, and was ruled by the O'Briens, who exercised a supreme authority over the whole, and who preserved their ascendancy here from the date of the earliest records to a late period. Few have more honorably distinguished themselves in the annals of their country than these chiefs and their brave Dalcassian followers, especially in the wars against the Danes, who long oppressed this country with their devastations, and formed permanent stations on the Shannon, at Limerick and Inniscattery. From these and from the entire district they were, however, finally expelled, early in the 11th century, by the well-directed efforts of the great Brien Boroihme, the head of the sept, and monarch of all Ireland, whose residence, and that of his immediate successors, was at Kinkora, near Killaloe.