Northern Jiangsu refers to five prefecture-level cities in the northern plain of Jiangsu, namely Xuzhou, Lianyungang, Suqian, Huai 'an and Yancheng, all of which are basically Jiangsu north of Huaihe River.

During the Spring and Autumn Period, Wu was actually one of the five tyrants in the Spring and Autumn Period. The largest area once reached northern Jiangsu, Anhui and southern Shandong (after defeating Qi). In the heyday of Wu, northern Jiangsu was the territory of Wu.

During the Three Kingdoms period, Wu and Subei were completely in the hands of Cao Wei, and Subei was not the territory of Wu.

During the Five Dynasties, part of northern Jiangsu was in Wu's hands. At present, Lianyungang, Huai 'an and Yancheng in northern Jiangsu are in Wu's hands, while Xuzhou and Suqian are in the hands of the later Tang Dynasty.

At the end of Yuan Dynasty, the State of Wu in Zhang Shicheng controlled the largest area, including northern Jiangsu.

At the end of the Yuan Dynasty, Zhu Yuanzhang was the king of Wu, Zhang Shicheng was, and Zhu Shixi was the kingdom of Wu. Later, Zhu Yuanzhang destroyed Zhang Shicheng, and Subei was naturally under the control of Zhu Yuanzhang's Western State of Wu. Later, he unified the south and became an emperor, with the title Daming.