Chinese Eastern Railway Liaodong from China in 1898. Officially, traffic on the line started in November 1901, but regular passenger traffic from St. Petersburg to Vladivostok across the Trans-Siberian railway did not commence until July 1903. In 1898, construction of a 550-mile (880 km) spur line, most of which later formed the South Manchuria Railway, began at Harbin, leading southwards through Eastern Manchuria, along the Liaodong Peninsula, to the ice-free deep-water port at Lüshun, which Russia was fortifying and developing into a first-class strategic naval base and marine coaling station for its Far East Fleet and Merchant Marine. This town was known in
Ulan-Ude Okrug. According to the 2010 Census, 404,426 people lived in Ulan-Ude; up from 359,391 recorded in the 2002 Census. In terms of population, it is the third largest city in eastern Siberia. The ethnic makeup of the city's population in 2010: The city is the center of Tibetan Buddhism in Russia and the important Ivolginsky datsan is located from the city. Ulan-Ude is located on the main line (Trans-Siberian line) of the Trans-Siberian Railway between Irkutsk and Chita at the junction of the Trans-Mongolian line (the Trans-Mongolian Railway) which begins at Ulan Ude and continues south through Mongolia to Beijing