In late 17th-century Britain, assessing a citizen's income was viewed as an unacceptable government intrusion into personal liberty. Seeking a revenue source to offset clipped coinage losses without creating an unpopular income tax, King William III introduced the Window Tax in 1696. The logic was deceptively simple: rich people lived in bigger houses with more windows, making the count of windows a convenient proxy for wealth.
Houses were charged a base tax plus an extra sum based on the number of glass openings beyond a threshold of ten. However, lawmakers grossly underestimated how far property owners would go to avoid paying it. Landlords and homeowners swiftly responded by boarding or bricking up window frames across the country, creating dark, windowless rooms and giving rise to the literal phrase daylight robbery.
The architectural consequences were striking and durable; entire streets featured grand brick facades punctuated by blanked-out window recesses, many of which remain visible throughout Britain and Ireland today. Beyond aesthetic disruption, the tax had disastrous public health consequences. The lack of natural light and proper ventilation in tenement buildings fostered ideal breeding grounds for diseases like cholera, typhus, and tuberculosis among urban poor populations who could not afford the higher rents caused by passed-down tax costs.
Despite decades of fierce opposition from medical authorities and social reformers, the notorious tax remained in force for over 150 years until its final repeal in 1851.