Zhongshan ([ʈʂʊ́ŋ ʂán]; Chinese: 中山) is a prefecture-level city in the south of the Pearl River Delta in Guangdong province, China, with a population of over 3 million (2012). The city-core subdistricts used to be called Shekki or Shiqi (石岐).
Zhongshan is one of a very few cities in China named after a person. It is named after Dr. Sun Yat-sen (1866–1925), who is known in Mandarin as Sun Zhongshan. Sun, the founding father of the Republic of China who is also regarded positively by the People's Republic, was born in Cuiheng village in Nanlang Township of what was then Xiangshan County. In 1925, the year after his death, Xiangshan was renamed Zhongshan in his honor.
Thousands of years ago, much of the Zhongshan area lay within the Pearl River estuary, with only scattered islands above the surface. Gradually from south to north, the area filled in with alluvial silt and became dry land. The northern parts of today's Zhongshan did not fill in until the time of the Ming Dynasty.
The Zhongshan area was part of an extended Dongguan County during the Tang Dynasty (618 – 907 AD), and was a significant sea salt producer. In 1082, during the Northern Song Dynasty, a fortified settlement called Xiangshan was founded in the area, marking the first official use of the name by which it would be known throughout most of its modern history. The prosperous settlement was then upgraded to a county in 1152. After the collapse of the Southern Song Dynasty, many descendants of Song court officials, including members of the imperial family, settled in Xiangshan. Under the Qing Dynasty, embankments were built to prevent flooding in the new alluvial lands, and the area of cultivation was extended.
Much of the First Opium War took place in and around Xiangshan. In 1839, the official Lin Zexu arrived in Xiangshan and ordered the expulsion of Sir Charles Elliot and other British traders from the area. Qing Dynasty soldiers resisted British attacks on the area in 1840, but were ultimately overwhelmed.
After the Opium Wars opened the region to foreign influence, a number of Xiangshan residents, including Sun Zhongshan (Yatsen), left to study overseas and were among the creators of modern China. Xiangshan was one of the first counties in China liberated as part of the Xinhai Revolution. After Sun Zhongshan's death in 1925, the commander-in-chief of the armed forces of the Republic of China decided to memorialize Sun by renaming his county of birth from Xiangshan to Zhongshan.
During the Second Sino-Japanese War, in July 1937, the Imperial Japanese Army seized several islands belonging to Zhongshan. During March 1940, the Japanese army occupied most of Zhongshan. The Japanese army implemented Unit 8604 or Nami Unit, a secret military medical unit, related to Unit 731, that researched biological warfare and other topics through human experimentation. It was headquartered at Zhongshan Medical University (Hal Gold, Unit 731 Testimony, 2003, p. 50). Nationalist and Communist units launched guerrilla attacks on Japanese forces beginning in 1942. On August 15, 1945, Japanese forces declared an unconditional surrender, and Zhongshan was liberated.
Zhongshan is located along the west side of the mouth of the Pearl River, directly opposite Shenzhen and Hong Kong. It lies south of Guangzhou and Foshan and north of Zhuhai and Macau. The northern part of Zhongshan, including most of the urbanized area, lies on the alluvial plains of the Pearl River Delta, while the southern part of the city's territory reaches into a range of coastal hills.
The most notable of these are the Wugui Hills (Chinese: 五桂山; pinyin: Wǔguī Shān; Jyutping: Ng5gwai3 Saan1). The city's current geography is typical of southern China: numerous steep mountains and hills with alluvial plains in between down to the coastline. The main summit of the Wugui Hills is the highest point in the city, at 531 metres (1,742 ft) above sea level.
Like nearly all of southern China, Zhongshan's climate is warm and humid most of the year, with an average temperature of 22 °C (72 °F) and 175 centimetres (69 in) of rainfall each year. Southern China experiences fairly frequent typhoons and thunderstorms, and most rain falls between April and September.