Luzhou, formerly transliterated as Lu-chou or Luchow, is a prefecture-level city located in the southeast of Sichuan Province, China. The city, named Jiangyang until the Southern and Northern Dynasties, is known as the "wine city". Situated at the confluence of the Tuo River and the Yangtze River, Luzhou is not only an important port on the Yangtze river, but also the largest port in both size and output in Sichuan province since Chongqing seceded from Sichuan province in 1997. At the 2010 census its population was 4,218,427 inhabitants whom 919,832 lived in the built-up (or metro) area made of Jiangyang and Longmatan districts, as Naxi district isn't conurbated yet. Luzhou, which borders Yunnan, Guizhou and Chongqing, is the only geographic junction of the four provinces, and was therefore the logical place for a port in ancient China. After the PRC was founded in 1949, Luzhou became the capital of southern Sichuan province. In 1983, Luzhou was approved as a prefecture-level city administratively.