It is difficult to get clarity on the origins of the sash window although the first mention is found in the late 1700's. A painting by Vermeer, 'The Milkmaid' has a woman standing in front of one. Around the same time the inventor Robert Hooke used the window in Ham House. However, the French word chassis refers to a frame and it is believed that via Holland the window came to Britain, and it is now inextricably linked to English culture.