A crossroads sea
The South China Sea is a large, partly enclosed body of water bordered by southern China, Vietnam, Cambodia, Thailand, Malaysia, Indonesia, Brunei and the Philippines, and by Taiwan on the northeast. It is the main waterway between the Indian Ocean (reached via the Strait of Malacca) and the East Asian seas. For at least two thousand years, goods, religions and people have moved across it.
Like the wider region, the sea follows the monsoon. Winds from the northeast prevail in winter and from the southwest in summer, so ships could sail south from China in the cooler months and north again in summer. Ports on the sea’s rim became places where merchants waited for the wind to change, and where cultures mixed. The same monsoon trade winds shaped the larger Indian Ocean trade.
Early networks
Austronesian-speaking peoples of Taiwan, the Philippines and coastal Southeast Asia had sailed these waters since prehistory, using outrigger canoes and plank boats. By the early centuries CE, kingdoms in the region were engaged in maritime commerce. Funan, centred on the Mekong delta, had a port at Oc Eo, where excavations found beads, seals and goods from India, the Mediterranean world and China, though the extent of Funan’s authority is debated. Later, Champa, along what is now central Vietnam, and Srivijaya, based on Sumatra, grew wealthy as intermediaries. Srivijaya in particular is generally thought to have controlled the straits around Malacca from around the seventh century.
Chinese records from the Han dynasty onward describe southern foreign trade and the products of the “southern seas”, often called the Nanhai. Guangzhou (Canton) was an early and long-lived port, receiving ships from the Indian Ocean as well as Southeast Asia.
Song and Yuan trade
From the Song dynasty onward, Chinese merchants and shipbuilders played a growing role. Quanzhou rose as a major port alongside Guangzhou, with foreign merchant communities, including Arab and Persian traders. Chinese ships carried ceramics, silk and metal goods south and brought back spices, aromatic woods, resins and tropical products. Chinese bronze coins circulated widely in the region.
The Mongol-led Yuan dynasty sent naval forces to Java in 1293 and to Vietnam, with limited success, though trade continued. Later travellers’ accounts mention the large Chinese ships in these seas.
Ming policy, tribute and the rise of Malacca
The early Ming government regulated overseas trade closely, favouring official tribute missions. The Zheng He voyages from 1405 to 1433 passed through the South China Sea, using ports such as Champa and Malacca as stopping places. Malacca, founded around 1400, was a key beneficiary: it offered a sheltered harbour, fair regulation and a position at the meeting point of the monsoons. As the Malacca spice port, it drew traders from India, Arabia, China, Java and elsewhere, and Chinese support helped establish its standing.
Private trade continued despite restrictions, and by the sixteenth century Chinese traders sailed to Vietnam, Siam, Java and the Philippines in large numbers. After the Portuguese took Malacca in 1511, they set up at Macau in the 1550s. The Spanish founded Manila in 1571, and its link with Chinese merchants at Fujian provided the silk and porcelain for the Manila galleons. Dutch and English companies followed, building trading posts such as Batavia, founded in 1619.
Ships and cargoes
Traffic on the South China Sea routes ran in several directions: north and south between China and the Malay world, and east to the Philippines. Many vessels were Chinese junks, with bulkheaded hulls and battened sails, but Southeast Asian builders also made large sewn-plank ships, and Malay and Javanese ships were well known to Chinese observers. Cargoes varied by period: Chinese ceramics were a common export for centuries, and Southeast Asian ships carried spices, tin, forest products and rice.
What shipwrecks tell us
Because written records are patchy, wrecks have become a major source. Several are well known:
- The Belitung wreck, found off Belitung island in the Java Sea in 1998, was an Arab-style sewn-plank vessel of around the ninth century carrying a very large cargo of Chinese ceramics, as well as gold and silver items. It shows direct trade between China and the Indian Ocean world at that early date.
- The Nanhai One, a Song-dynasty merchant ship that sank off the coast of Guangdong, was raised in 2007 in a large container, and then excavated at a museum site.
- The Tek Sing, a Chinese junk that sank in 1822 in the Gaspar Strait region, was salvaged in 1999. The recovery of a huge quantity of porcelain was controversial, partly because commercial salvage sold the finds at auction.
Fishermen and trawlers have also recovered ceramics from the sea floor for decades. Archaeologists generally prefer careful excavation over commercial recovery, because the ship’s structure and the context of cargo are lost when objects are simply lifted. The field of maritime archaeology treats such wrecks as evidence for trade, shipbuilding and daily life.
The modern sea
The South China Sea remains one of the world’s busiest shipping areas and fishing grounds. Its modern political disputes are outside the scope of this historical overview, but the older picture is clear: it was a shared sea of exchange, and no single state ever fully controlled its trade.