Zhongshan (; ) is a prefecture-level city in the south of the Pearl River Delta in Guangdong province, China. As of the 2020 census, the whole city with 4,418,060 inhabitants is now part of the Guangzhou–Shenzhen conurbation with 65,565,622 inhabitants. The city-core subdistricts used to be called Shiqi or Shekki (). Zhongshan is one of the few Chinese cities to be named after a person. It was originally named Xiangshan (, "Fragrant Mountain"; Cantonese: Heung-saan), but was renamed in 1925 in honor of Sun Yat-sen, who is known in China as "Sun Zhongshan". Sun was the founding father of the Republic of China who is also regarded positively by the People's Republic. He was born in Cuiheng village in Nanlang Township of what was then Xiangshan County. Names Until 1925, Zhongshan was generally known as Xiangshan or Heung-san (Siangshan) (), in reference to the many flowers that grew in the mountains nearby. The city was renamed in honor of Sun Yat-sen, who had adopted the name Zhongshan. Sun is considered by both the People's Republic of China and the Republic of China to be the "Father of Modern China", and was from Cuiheng village – now part of Nanlang Town in Zhongshan. History 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. Significant land formation in the area of Zhongshan occurred since Ming Dynasty. 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,