An English tax on any window or window‐like opening, which was in force from 1695 to 1851. It was originally imposed to pay for the losses of the great recoinage of 1695 and was increased six times in the 18th century, particularly by Pitt the Younger. The tax was eventually applied to all windows in excess of six in a building and windows bricked up to avoid the tax can still be seen in older houses throughout Britain.