Changzhou is a prefecture-level city located in southern Jiangsu province, China. Situated on the southern bank of the Yangtze River, the city shares borders with Nanjing to the west, Zhenjiang to the northwest, Wuxi to the east, and the province of Zhejiang to the south.
Historically, the city has been known by various names, including Yanling, Lanling, and Jinling. As of the 2020 census, the population of the Changzhou Municipality was recorded at 5,278,121. The city is also notable as the birthplace of Zhou Youguang, who developed the pinyin romanization system.