These photographs of Russian cities, once the centres of Russian duchies, were taken by a renowned Russian photographer Sergey Mikhaylovich Prokudin-Gorsky (Rus: Сергей Михайлович Прокудин-Горский) in early XX century. The method of colour photography he used was based on capturing colour on three separate black-and-white photographs, taken through a red, green, and blue filters. With the support of Tsar Nicholas II, Prokudin-Gorsky photographed the Russian Empire around 1909 through 1915.