In the second year of Yongle in the Ming Dynasty (1404), the city was built and defended, which was called "Tianjinwei". It began with the opening of the Grand Canal in Sui Dynasty. After the mid-Tang Dynasty, Tianjin became a land and water terminal for transporting grain from south to north. Song and Jin Dynasties called it "Zhigu Village", and Yuan Dynasty renamed it "Haijin Town", which was a military town and a water transportation center. 1368 after the establishment of the Ming dynasty, Zhu Yuanzhang, the Ming emperor, made his sons kings and stationed in various places in order to consolidate the rights of the dynasty. The fourth son, Judy, was made a prince and stationed in Beijing. 1398, Zhu Yuanzhang died of illness. Due to the early death of the Prince, Zhu Yunwen, the eldest grandson of Zhu Yuanzhang, inherited the throne, which was called the throne in history. After decades of hard work, Judy, the prince of Yan, is the strongest of these kings. Due to his mediocrity and incompetence, as well as his own political ambitions, Judy competed with his nephew Wen Jian for the throne in the name of "Jingnan" in 1400. Judy led troops to attack Cangzhou from zhi gu, the predecessor of Tianjin. After several years of war, he finally captured Nanjing and seized the throne. 1402, Judy became emperor of the Ming dynasty, with the year number "Yongle". In order to commemorate the "land of Longxing" where he sent his troops, Judy named "Zhigu" Tianjin Wei. "Heaven" means the son of heaven, and "Tianjin" means the ferry. After Tianjin was given the name, the military department was established in the same year. "Wei" is the military establishment of the Ming Dynasty. Tianjin Wei also began to build cities. When it was first built, Tianjin was actually a tucheng. This earthen city is more than 9 miles in circumference, 3 feet high and 2 feet wide. The shape of the city is long from east to west and short from north to south, much like an abacus, so people also called it "abacus city" at that time. At that time, Tianjin had Tianjinwei, Tianjin Zuo Wei and Tianjin Youwei, which were collectively called Sanwei. So far, the word "Tianjin Wei" often mentioned by people comes from this. 65438+February 23rd, 2004 is the anniversary of the 600th anniversary of Tianjin fortification.