Tianjin simply known as Jin is situated in the northeastern part of North China Great Plain, bordering the Bohai Sea in the east, leaning against the Yuanshan Mountain in the north, with its terrain traversing the Haihe River through north and south. It has become the hub of communications of North China and the gateway of the capital city.

Tianjin was once part of Bohai Sea in the remote antiquity. During the Pre-Qin days, Tianjin once belonged to the Yan and Qi kingdoms of the Warring States. In the Western Han Dynasty, the Tinajin region mainly was part of the Yuyang prefecture, Quanzhou county, the Bohai prefecture and Zhangwu county.

The original name of Tianjin was "Zhigu". It was changed into Tianjin in early Ming Dynasty. In 1398, Zhu Di dispatched troops from Beijing in the pretext of "pacification of rebellion", and defeated Zhu Yun Wen and became Emperor. In commemoration of the place where he crossed the river moving southward, he renamed the place "Tianjin" by imperial order, meaning "the place from where the emperor crossed the river" and stationed "Tianjin Guards" there. From then on Tianjin is also called "Tianjin Guards".

Tianjin was built in the 2nd year (1404) of the reign of Emperor Yong Le of the Ming Dynasty.

Tianjin was a seaport and an important gateway of the capital city during the Qing Dynasty. The transport of grain by water to the capital continued to develop and it became the economic center in the north. (enorth.com.cn)

Source:China.org.cn