downing street is a few minutes' walk from the houses of parliament. the street was built in the 1680s by sir george downing, 1st baronet (1632–1689) on the site of a mansion called hampden house. the prime minister, the chancellor of the exchequer, and the chief whip all have official residences in buildings along one side of the street. the houses on the other side were all replaced by the foreign office in the nineteenth century.