Bao'an County
Shenzhen roughly follows the administrative boundaries of Bao'an County, which was established since imperial times. The southern portion of Bao'an County was seized by the British after the Opium Wars and became Hong Kong, while the village of Shenzhen was situated on the border. Due to the completion of a train station that was the last stop on the Mainland Chinese section of the railway between Guangzhou and Kowloon, Shenzhen's economy grew and became a market town and later a city by 1979, absorbing Bao'an County for the next decade.