Aldborough was built on the site of a major Roman garrison town, Isurium Brigantum, which marked the crossing of Dere Street (the Roman Road running north out of York) over the River Ure. Isurium was the base of the Ninth Legion, and was also the administrative centre of the Brigantes, the most populous British tribe in the area at the time of the Roman occupation. The Aldborough Roman Site museum, run by English Heritage, contains a number of relics of the Roman town, including some colourful tesselated pavements.
Aldborough lost much of its importance when the river crossing was moved to nearby Boroughbridge in Norman times. Nevertheless, in the Middle Ages it was made a Parliamentary Borough, and returned two Members of Parliament until the seat was abolished in the Great Reform Act of 1832. Aldborough was a "scot and lot" borough, meaning that any man paying the poor rate was eligible to vote. Nevertheless, it was a small borough (not even including the whole parish of Aldborough, since Boroughbridge, also within the boundaries, was also a borough with its own two MPs), and by the time of the Reform Act it had an electorate of less than 100. This made it a pocket borough and easy for the local landowner to dominate.
In the 18th century, Aldborough was controlled by the Duke of Newcastle. In April 1754 Newcastle, who had just become Prime Minister, selected his junior colleague and future Prime Minister, William Pitt (Pitt the Elder), to sit as its MP. Pitt represented Aldborough for two-and-a-half years, but having fallen out with Newcastle and been dismissed from his ministry, he was forced to find a new constituency when he was re-elected to Parliament in 1756.
*D Englefield, J Seaton & I White, Facts About the British Prime Ministers (London: Mansell, 1995) *Michael Brock, The Great Reform Act (London: Hutchinson, 1973). *Frederic A Youngs, Jr, Guide to the Local Administrative Units of England, Volume I (London: Offices of the Royal Historical Society, 1979)
