County Louth is a county in Ireland. It is part of the Border Region and is also located in theprovince of Leinster. It is named after the town of Louth. Louth County Council is the local authority for the county. The population of the county is 122,897 according to the 2011 census.
The official spelling in Irish, Lú, is derived from Lughbhaidh – the Celtic pagan god Lugh, whose festival is celebrated at Lughnasadh (Lúnasa). This is a county steeped in myth, legend and history, going back to the pre-historic days of the Táin Bó Cúailnge (Cooley Cattle Raid, see Cú Chulainn). Later it saw the influence of the Vikings as seen in the name of Carlingford Lough. They also established a longphort at Annagassan in the ninth century. At this time Louth consisted of three sub-kingdoms each subject to separate over-kingdoms: Conaille (Ulaidh); Fir Rois (Airgialla); and, the Fir Arda Ciannachta (Midhe). The whole area became part of the O’Carroll Kingdom of Airgialla (Oriel) early in the twelfth century.