“Indochina” was a nineteenth-century name for a six-country peninsula
Mainland Southeast Asia—Cambodia, Laos, Myanmar, Peninsular Malaysia, Thailand, Vietnam, and sometimes Singapore—is the continental half of Southeast Asia. Nineteenth-century scholars coined “Indochina” to flag Indian and Chinese cultural overlap before French administrators borrowed the label for their colony.
Conrad Malte-Brun wrote indo-chinois in 1804; John Leyden spoke of Indo-Chinese peoples in 1808. Malte-Brun later doubted his own term for overplaying China. French Indochina covered today’s Cambodia, Laos, Vietnam, and some Chinese fringe; modern usage prefers Mainland versus Maritime Southeast Asia for the island world.
Indian texts offer Yāvadvīpa and the debated Suvarṇabhūmi—“land of gold”—which may point to mainland or insular zones. Biogeographers map an Indochinese bioregion inside the Indomalayan realm, distinct from the Malesian island flora. Geographically the peninsula projects from Asia between India and China, entirely north of the equator. The South China Sea, the Strait of Malacca and the Andaman Sea divide it from the island world, and it borders China to the north, India and Bangladesh to the west, and Indonesia and the Philippines across the water.
The Mekong, at 4,900 kilometres the longest river in Southeast Asia, rises on the Tibetan Plateau and drains some 795,000 square kilometres across Myanmar, Laos, Thailand, Cambodia and Vietnam. Cambodia’s Tonlé Sap swells to as much as 16,000 square kilometres, the region’s largest freshwater lake, and the Gulf of Thailand spans 320,000 square kilometres yet averages only 45 metres deep.
Elevations run from Hkakabo Razi in Myanmar at 5,881 metres down to the Boh Yai mine in Thailand’s Kanchanaburi Province, at least 106 metres below sea level. Northern Myanmar, Laos and Vietnam are temperate, while the centre is largely tropical savannah. Every country counted in the region belongs to ASEAN.
Source: Mainland Southeast Asia
