Who can tell me what "Tianjin Wei" means?

The development history of Tianjin can be traced back to the pre-Qin period, and the geographical concept of "Tianjin" came into being in the Ming Dynasty. At that time, Emperor Judy moved the capital to Beijing and passed by Sanjiangkou several times. Considering that the seaside is unguarded, there will be no family, and foreign invasion will endanger the country, so he was transferred to the Huaijia army to guard. (For the deployment of troops, you can take an examination of historical data. ) Because the son of heaven crossed the river, it was given the name of Tianjin to expand its village and increase its defense. Set up guards according to the military establishment of the Ming Dynasty. With 5,600 staff, it seems impossible to guard the gates of these two capitals. Later, it was merged into Tianjin Zuo Wei and Tianjin Youwei, and Tianjin Weiwei became the largest Weiwei in China.