Aldborough is a village in the civil parish of Boroughbridge, part of the Borough of Harrogate in North Yorkshire, England. Historically a part of the West Riding of Yorkshire, what is now known as Aldborough was built on the site of a major Romano-British town, Isurium Brigantum. The Brigantes, the most populous Celtic tribe in the area at the time of the Roman occupation of Britain, used the settlement as a capital. Isurium may also have been the base of the Roman Legio VIIII Hispana.