Province (pop., 2002 prelim.: 2,105,449), eastern Ireland.
It covers an area of 7,580 sq mi (19,633 sq km). Its counties include Carlow, Dublin , Kildare, Kilkenny, Laoighis, Longford, Louth, Meath, Offaly, Westmeath, Wexford, and Wicklow. Its northern part, Meath, was a separate kingdom in the 2nd century AD. In the early Middle Ages, kings of Leinster fought constantly against the Uí Néill, the line of high kings whose capital was at Tara in Meath. In the late 15th and early 16th centuries, Leinster was virtually independent, under the earls of Kildare.