Ho Chi Minh City (HCMC; Vietnamese: Thành phố Hồ Chí Minh), also known as Saigon (Vietnamese: Sài Gòn), is the most populous city in Vietnam, with a population of around 10 million in 2023.[7] The city's geography is defined by rivers and canals, of which the largest Saigon River is named after. As a municipality, Ho Chi Minh City consists of 16 urban districts, five rural districts, and one municipal city (sub-city). As the largest financial centre in Vietnam, Ho Chi Minh City has the highest gross regional domestic product out of all Vietnam provinces and municipalities,[8] contributing around a quarter of the country's total GDP.[9] Ho Chi Minh City's metropolitan area is ASEAN's 6th largest economy, also the biggest outside an ASEAN country capital. Since ancient times, water transport has been heavily used by inhabitants in the area. The area was occupied by Champa from 2nd century AD to around the 19th century, due to Đại Việt's expansionist policy of Nam tiến. After the fall of Citadel of Gia Định, Saigon was the capital of French Indochina from 1887 to 1902, and again from 1945 until its cessation in 1954. Following the partition of French Indochina, it became the capital of South Vietnam until it was captured by North Vietnam, who renamed the city after their former leader Hồ Chí Minh, though the former name is still widely used in informal usages. Beginning in the 1990s, the city underwent rapid expansion and modernization, which contributed to Vietnam's post-war economic recovery and helped revive its international trade hub status.