A quake-prone crossroads holds 676 million people
Southeast Asia, south of China and east of India, covers about 4.5 million square kilometres—nearly 10 percent of Asia and 3 percent of Earth’s land—yet holds some 676 million people, about 8.5 percent of humanity. It is Asia’s third-most populous region after South and East Asia.
Two seismic belts meet in Indonesia: the Alpide belt, running through the ranges of Myanmar, Thailand, Peninsular Malaysia, Sumatra, Java and Bali, and the Pacific Ring of Fire, which takes in the Philippines, eastern Indonesia and Timor-Leste. That collision explains the frequent quakes and eruptions, especially in the Philippines and Indonesia. The mainland lies wholly north of the equator, while Timor-Leste and southern Indonesia sit south of it. East of the Wallace Line, the islands' animals look more like Oceania's.
Europeans long called the region the East Indies, and Chinese sources called it Nanyang, the Southern Ocean. American pastor Howard Malcolm first used the phrase 'South-Eastern Asia' in 1839, applying it only to the mainland, and the Allies' South East Asia Command popularised it from 1943, although that command left out the Philippines and much of Indonesia while including Ceylon. A roughly standard definition emerged only by the late 1970s. All eleven countries now belong to ASEAN, Timor-Leste having joined in 2025.
Homo erectus lived here about 1.5 million years ago, and Homo floresiensis survived until at least 50,000 years ago. Cave paintings on Sulawesi and Borneo, 40,000 to 60,000 years old, are the oldest known rock art in the world. With seas far lower, western Indonesia and the Malay Peninsula formed one landmass called Sundaland, and the Gulf of Thailand was dry land. Genetic studies trace a basal eastern Eurasian lineage to the mainland around 50,000 BC, which later branched into Papuan-related and East Asian-related populations.
Seafaring Austronesians spread from Taiwan, reaching the northern Philippines between 7000 and 2200 BC and Borneo by 1500 BC. Most people in Indonesia, Malaysia, Brunei, the Philippines and Timor-Leste descend from them. Indian, Chinese, Muslim and later European influences shaped the region's institutions, and Japan briefly occupied several countries during the Second World War.
Source: Southeast Asia
