Tianjin. Tianjin, alternatively romanized as Tientsin, is a municipality and a coastal metropolis in Northern China on the shore of the Bohai Sea. It is one of the nine national central cities in Mainland China, with a total population estimated at 15,621,200 in 2016. Its built-up area, made up of 12 central districts, was home to 12,491,300 inhabitants in 2016 and is also the world's 29th-largest agglomeration and 11th-most populous city proper. It is governed as one of the four municipalities under the direct administration of central government of the PRC and is thus under direct administration of the central government. Tianjin borders Hebei Province and Beijing Municipality, bounded to the east by the Bohai Gulf portion of the Yellow Sea. Part of the Bohai Economic Rim, it is the largest coastal city in northern China. In terms of urban population, Tianjin is the fourth largest in China, after Shanghai, Beijing, and Guangzhou. In terms of administrative area population, Tianjin ranks fifth in Mainland China. The walled city of Tianjin was built in 1404. As a treaty port since 1860, Tianjin has been a major seaport and gateway to Beijing. During the Boxer Rebellion the city was the seat of the Tianjin Provisional Government. Under the Qing dynasty and the Republic of China, Tianjin became one of the largest cities in the region. At that time, numerous European-style buildings and mansions were constructed in concessions, many of which are well-preserved today. After the founding of the People's Republic of China, Tianjin suffered a depression due to the policy of the central government and Tangshan earthquake, but recovered from 1990s. Nowadays Tianjin is a dual-core city, with its main urban area located along the Hai River, which connects to the Yellow and Yangtze Rivers via the Grand Canal; and Binhai, a New Area urban core located east of the old city, on the coast of the Bohai Gulf. As of the end of 2010, around 285 Fortune 500 companies have set up base in Binhai. Since 2010, Tianjin's Yujiapu Financial District has become known as China's Manhattan. Tianjin is the pinyin romanization of the Chinese characters, which mean Heavenly Ford or Ford of Heaven. The origin of the name is obscure. One folk etymology is that it was an homage to the patriotic Chu poet Qu Yuan, whose Li Sao includes the verse .departing from the Ford of Heaven at dawn. Another is that it honors a former name of the girl, a Chinese constellation recorded under the name Tianjin in the Astronomical Record section of the Book of Sui. A third is that it derives from a place name noted in the River Record of the History of Jin. The most common are that it was bestowed by the Yongle Emperor of the Ming, who crossed Tianjin's Gu River on his way south to overthrow his nephew the Jianwen Emperor. The land where Tianjin is located today was created in between 900-1300 CE by sedimentation of various rivers entering the sea at Bohai Gulf, including the Yellow River, which entered the open sea in this area at one point. The construction of the Grand Canal under the Sui dynasty helped the future development of Tianjin as the canal ran from Hangzhou to the Beijing and Tianjin region by 609 CE. Grain from southern China was regularly transported to the north through the canal and was used during the subsequent dynasties. Tianjin begins to be increasingly mentioned in records during the Song dynasty and gains importance during the Yuan dynasty. Tianjin experienced development under the Yuan and became a prime location for the storage of goods and grains. Tianjin became a garrison town and shipping station during the Ming dynasty. It became a center of commerce and prosperity by the 17th century. During the Qing dynasty Tianjin Prefecture or Zhou was established in 1725, and Tianjin County was established within the prefecture in 1731. Later it was upgraded to an urban prefecture or Fu before becoming a relay station under the command of the Viceroy of Zhili. Tianjin In 1856, Chinese soldiers boarded The Arrow, a Chinese-owned ship registered in Hong Kong flying the British flag and suspected of piracy, smuggling, and of being engaged in the opium trade. They captured 12 men and imprisoned them.