The Great Smog was a severe air pollution event that affected London, England, in December 1952. A period of unusually cold weather, combined with an anticyclone and windless conditions, collected airborne pollutants—mostly arising from the use of coal—to form a thick layer of smog over the city. It lasted from Friday, 5 December to Tuesday, 9 December 1952, then dispersed quickly when the weather changed.

Key figuresTheodoric the GreatAlfred the GreatOtto I the GreatHenry I of EnglandAbbas the Great