The trade network of India and Southeast Asian lands and islands in early history gave rise to the growth of trade centres visited by various foreign peoples. Around the fifth century two famous routes known as the (overland) “silk roads” stretched from China, through Central Asia, and Turkestan to the Mediterranean Sea. These roads were connected to the Indian caravan tracks. Another route ran through the sea, extending from China, through the Malacca Strait and Indonesian waters, towards India and the western Indian Ocean (Sjafei 1981–82, pp. 49–50).

The continuous trade activities and voyages caused the emergence of a number of seaports in the Indian Ocean. According to Wolters, this development was responsible for the birth of the Sumatran Sriwijaya kingdom (Wolters 1967). Indeed, Sriwijaya came to be a significant transitory trading seaport much frequented by merchants from across the globe. Sriwijaya was the first power in Indonesian history successful in dominating the Malacca Strait areas and in holding the key to the trade and passages to China, India, and other countries.

Sumatra had been strategically located for international trade across the oceans since prehistoric times, most likely due to the trade of spices, a commodity much sought after across the world. Rouffaer's research unfolded (1900) a series of findings of bronze drums from Southeast Asian soil, continuing along a curved line through Sumatra, Bali, Nusa Tenggara, to the Kei Island in Southeast Maluku, demonstrating evidence of a busy spice trade. Rouffaer also mentions that some European sources had knowledge of spices produced by the Indonesian archipelago (Lapian 1979, p. 96).

A country that relies entirely on trade heavily depends on the trade patterns it develops. Inscriptions from the time Sriwijaya was enjoying its peak of prosperity (early seventh century) suggest the kingdom's expansion into surrounding territories. Its northern extension, for instance, was not only intended to keep watch over the exit and entrance to the strait, but was also meant to control the overland crossing of Tanah Genting Kra. In addition, the expedition planned to conquer Bhumi Jawa may be construed as an effort to subdue West Java, that is, a strategy to annex the lands on both sides of the Sunda Strait to the kingdom (Lapian 1979, p. 97).