The counties of the United Kingdom are subnational divisions of the United Kingdom, used for the purposes of administrative, geographical and political demarcation. By the Middle Ages counties had become established as a unit of local government, at least in England. By the early 17th century all of England, Wales, Scotland and Ireland had been divided into counties. The older term "shire" was historically equivalent to "county". In Scotland shire was the only term used until after the Act of Union 1707.