Bao'an County
The area encompassed by Shenzhen and Hong Kong was formerly belonged to Bao'an County in imperial times. After the Qing defeat in the Second Opium War, the United Kingdom seized Hong Kong Island and was leased the New Territories, forming the modern-day boundaries between Hong Kong and Shenzhen (the successor to Bao'an). The two cities are separated by two bays: Shenzhen Bay and Mirs Bay, and a river: Sham Chun River. According to then-Executive Council member Leung Chun-ying, the two cities' close relationship can be due to the close distance between the two, similar economic systems, differences in wages and price levels, and that the two cities have different systems compared to other Chinese cities, with Hong Kong embracing the one country, two systems principle while Shenzhen is a SEZ.