County Waterford is colloquially known as "The Déise", pronounced "day-shih" or, in Irish, /dʲe:ʃʲɪ/ . Some time between the 4th and 8th centuries, an Irish tribe called the Déisi were driven from southern county Meath/north Kildare and moved into the Waterford region, conquering and settling there. The ancient principality of the Déise is today roughly coterminous with the current Roman Catholic Diocese of Waterford and Lismore thus including part of south County Tipperary. The westernmost of the baronies are "Decies within Drum" and "Decies without Drum", separated by the Drum-Fineen hills. There are many megalithic tombs and ogham stones in the county. The Viking influence can still be seen with Reginald's Tower, one of the first buildings to use a brick and mortar construction method in Ireland. Woodstown, a settlement dating to the 9th century was discovered 5.5 kilometres west of Waterford city. It was the largest settlement outside Scandinavia and the only large-scale 9th-century Viking settlement discovered to date in Western Europe. Other architectural features are products of the Anglo-Norman invasion of Ireland and its effects.
As of 1 June 2014, Waterford City and County Council is the local government authority for Waterford. The authority was formed following the merger of Waterford City Council and Waterford County Council. The merger occurred following the Local Government Reform Act 2014. Each local authority ranks equally as first level local administrative units of the NUTS 3 South-East Region for Eurostat purposes. There are 31 LAU 1 entities in the Republic of Ireland. The local authority is responsible for certain local services such as sanitation, planning and real-estate development, libraries, the collection of automobile taxation, local roads and social housing. The county is part of the South constituency for the purposes of European elections. For elections to Dáil Éireann, the county is part of two constituencies: Waterford and Tipperary South. Together they return 7 deputies to the Dáil. The Electoral Act 2009 defines the Waterford constituency as "The county of Waterford, except the part thereof which is comprised in the constituency of Tipperary South; and the city of Waterford."
Gaeltacht
Gaeltacht na nDéise is a Gaeltacht area in Co. Waterford consisting of the parish of An Rinn and An Sean Phobal. Gaeltacht na nDéise is located 10 km from the town of Dungarvan, has a population of 1,816 people and encompasses a geographical area of 62 km2. According to Census 2016 the percentage of daily Irish speakers in Gaeltacht na nDéise was 45.6%.