Zhou were historical administrative and political divisions of China. Formally established during the Han dynasty, zhou existed continuously for over 2000 years until the 1912 establishment of the Republic of China. Zhou were also once used in Korea, Vietnam and Japan .

Hangzhou is the capital and most populous city of Zhejiang, China. It is located in the northeastern part of the province, sitting at the head of Hangzhou Bay, which separates Shanghai and Ningbo. Hangzhou grew to prominence as the southern terminus of the Grand Canal and has been one of China's most renowned and prosperous cities for much of the last millennium. It is a major economic and e-commerce hub within China, and the second biggest city in the Yangtze Delta after Shanghai. Hangzhou is classified as a sub-provincial city and forms the core of the Hangzhou metropolitan area, the fourth-largest in China after Guangzhou-Shenzhen Pearl River agglomeration, Shanghai-Suzhou-Wuxi-Changzhou conurbation and Beijing. As of 2022, the Hangzhou metropolitan area was estimated to produce a gross metropolitan product (nominal) of 4 trillion yuan, making it larger than the economy of Sweden. As of the 2020 Chinese census, it had a total population of 11,936,010 inhabitants. However, its metropolitan area, populated by 13.035 million people over an area of 8,107.9 km2 (3,130.5 sq mi), consists of all urban districts in Hangzhou and 3 urban districts of the city of Shaoxing.