The rivalry between the Sumatran Srivijaya and…

The rivalry between the Sumatran Srivijaya and Javanese Medang had become more hostile in 1005.

The animosity was probably caused by the Srivijayan effort to reclaim Sailendra lands in Java, as Balaputra and his offspring—a new dynasty of Srivijaya maharajas—belong to the Sailendra dynasty, or by Medang aspirations to challenge Srivijaya dominance as the regional power.

Dharmawangsa had launched a naval invasion of Srivijaya in 990 and unsuccessfully attempted to capture Palembang.

Dharmawangsa's invasion had caused the Maharaja of Srivijaya, Chulamaniwarmadewa to request protection from Song dynasty China.

Srivijaya manages to repel the Medang invaders in 1006.