Tianjin is China 's third largest city, an independent municipality with a population of 9.5 million that is a major commercial and industrial center as well as the biggest port in north China . 137 kilometers (85 miles) southeast of Beijing , Tianjin is situated at the confluence of five tributaries of the Haihe River , 50 km from the Gulf of Bohai .

Tianjin is best known for its streetscapes of colonial era buildings, a residue of its status as a Treaty Port after 1858. Now a center of multinational businesses concentrated in the new satellite city known as TEDA (Tianjin Economic Development Area), Tianjin has an extensive modern infrastructure, and is known for the high quality of its industrial products.

Early settlement in the Tianjin region date s back to the Warring States period, but Tianjin 's later prominence was primarily tied to the rise of nearby Beijing as the capital of northern nomadic dynasties and later of the country as a whole. Tianjin served primarily as a storage, sale, and distribution center for agricultural products from the south in the 12th century. Under the Mongols, who first established Beijing as the capital of the entire country, Tianjin served as a storage and trans-shipment point for the grain taxes that were shipped from the south

Tianjin 's prosperity proved a lure for Western trading nations. In 1856 British and French troops used the boarding of a British ship by Chinese troops in search of pirates as an excuse to attack the forts guarding the Hai he River . The defeated Chinese were forced to sign the 1858 Treaty of Tianjin, which opened the port to foreign trade and the sale of opium. Other European nations and Japan followed, establishing distinctive independent concessions on the riverside areas, each with a distinctive architectural style -- variously English Victorian, Italian Roman style streets, French chateaux styles, and German Bavarian villas.