金史
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 ..." (, "zhāo fārèn yú Tiānjīn xī"). 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 is 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.