Photographer Sergei Prokudin-Gorskii undertook a photographic survey of the Russian Empire from 1903 to 1915 using a specialized three-color photography process. His photos provide a detailed visual record of the diverse peoples and landscapes within the massive empire, which at its peak stretched across Eastern Europe and Northern Asia and encompassed over 8 million square miles, nearly 1/6 of the Earth's land. The high quality of Prokudin-Gorskii's color photographs, some 100 years old, make it difficult to believe they were taken so long ago.