Sergei Progudin-Gorskii was a Russian photographer.
He's mostly famous for his photographic survey of Russia in 1909-1912 and 1915. The survey was supported by Czar Nicholas II, and Prokudin-Gorskii used a specially equipped railroad car for this journey.
Before the Russian Revolution in 1918, he left Russia and went to Norway, England and then finally to France. His photographs show the glory of the Russian empire just before the revolution.
The photography technique was pretty unusual for the time: Basically, he used Technicolor before it was invented. The camera he used took three pictures on three glass negatives (one for each primary color). In his time, the images could only be viewed using a special projector.
In the digital age, the pictures have been scanned and combined. The quality of his pictures is way too good - our puny little brains can't understand that these glorious photos were, in fact, taken almost a century ago. =)
As of writing, the US Library of Congress has a very good website of Prokudin-Gorskii's work: http://www.loc.gov/exhibits/empire/