The division of Ireland into counties was introduced gradually by Norman and English settlers between the 13th and 17th centuries, reflecting their use in in the Kingdom of England as units of local government. Townlands, civil parishes and baronies are subdivisions of counties. The 6” survey of Ireland carried out under the 1825 Boundary Survey Act documented and formalised the boundaries of the thirty-two counties of Ireland. Counties are statute boundaries under the 19th century Boundary Survey Acts and can only be altered by statutory instrument. This dataset is a digital representation of the statutory boundary as shown on the relevant historic mapping and includes alterations brought about by statutory instruments.There are 26 counties in the republic of Ireland. This dataset is provided by Tailte Éireann.