San Antonio (/ˌsæn ænˈtoʊnioʊ/ SAN an-TOH-nee-oh; Spanish for "Saint Anthony"), officially the City of San Antonio, is a city in Texas, United States. The city is the seventh-most populous in the United States, the second-largest in the Southern United States, and the second-most populous in Texas. It is the 12th most-populous city in North America, with 1,434,625 residents in 2020.
Founded as a Spanish mission and colonial outpost in 1718, the city in 1731 became the first chartered civil settlement in what is now present-day Texas. The area was then part of the Spanish Empire. From 1821 to 1836, it was part of the Mexican Republic. It is the oldest municipality in Texas, having celebrated its 300th anniversary on May 1, 2018.
Zhongshan, known as "Xiangshan" in ancient times, is a prefecture-level city in Guangdong Province, one of the five prefecture-level cities in the country without zones, one of the central cities in the Pearl River Delta, an important node city in Guangdong-Hong Kong-Macau Greater Bay Area, and one of the regional central cities in Guangdong. It has maintained the fifth economic output of Guangdong Province for many years, and is known as the four tigers of Guangdong together with Shunde, Nanhai and Dongguan. Xiangshan County, formerly known as Xiangshan County, was established in 1152. In 1925, it was renamed Zhongshan County in memory of Sun Yat-sen. It is located at the lower reaches of the West and Beijiang River south-central of the Pearl River Delta, with Panyu District of Guangzhou City and Shunde District of Foshan City to the north, Jiangmen City, Xinhui District and Doumen District of Zhuhai City to the west, Zhuhai City to the southeast and Zhujiang Estuary to the east.