Pala chola

Throughout most of their shared history, ancient India and Indonesia enjoyed friendly and peaceful relations, therefore this Indian invasion is a unique event in Asian history. In 9th and 10th centuries, Srivijaya maintained close relations with the Pala Empire in Bengal, and an 860 Nalanda inscription records that Maharaja Balaputra of Srivijaya dedicated a monastery at the Nalanda university in Pala territory. The relation between Srivijaya and the Chola dynasty of southern India was friendly during the reign of Raja Raja Chola I. In 1006 CE a Srivijayan Maharaja from Sailendra dynasty — king Maravijayattungavarman — constructed the Chudamani Vihara in the port town of Nagapattinam.[14] However, during the reign of Rajendra Chola I the relations deteriorated as the Cholas attacked Srivijayan cities.[15]

The Cholas are known to have benefitted from both piracy and foreign trade. Sometimes Chola seafaring led to outright plunder and conquest as far as Southeast Asia.[16] While Srivijaya that controlled two major naval choke points; Malacca and Sunda Strait; at that time was a major trading empire that possess formidable naval forces. Malacca strait's northwest opening was controlled from Kedah on Peninsula side and from Pannai on the Sumatran side, while Malayu (Jambi) and Palembang controlled its southeast opening and also Sunda strait. They practiced naval trade monopoly that forced any trade vessels that passed through their waters to call on their ports or otherwise being plundered.

The reasons of this naval expedition are unclear with Nilakanta Sastri suggesting that the attack was probably caused by Srivijayan attempt to throw obstacles in the way of the Chola trade with the East (especially China), or more probably, a simple desire on the part of Rajendra to extend his digvijaya to the countries across the sea so well known to his subject at home, and therefore add luster to his crown.[17] Another theory suggests that the reasons of the invasion was probably motivated by geopolitics and diplomatic relations. King Suryavarman I of the Khmer Empire requested aid from Rajendra Chola I of the Chola dynasty against Tambralinga kingdom.[18] After learning of Suryavarman's alliance with Rajendra Chola, the Tambralinga kingdom requested aid from the Srivijaya king Sangrama Vijayatungavarman.[18][19] This eventually led to the Chola Empire coming into conflict with the Srivijaya Empire. This alliance was somewhat also has religious nuance, since both Chola and Khmer empire are Hindu Shivaist, while Tambralinga and Srivijaya are Mahayana Buddhist.