Taking advantage of this internal strife Rajaraja I invaded Anuradhapura sometime in 993 AD and conquered the northern part of the country and incorporated it into his kingdom as a province named "Mummudi-sola-mandalam" after himself.The Chola official Tali Kumaran erected a Shiva temple called Rajarajeshvara ("Lord of Rajaraja") in the town of Mahatirtha (modern Mantota, Mannar), which was renamed Rajaraja-pura.[14] According to the Culavamsa and Karandai plates, Rajendra Chola led a large army into Rohana and captured Mahinda's crown, queen, daughter, a vast amount of wealth, and the king himself whom he took as a prisoner to India, where he eventually died in exile in 1029.But he died before he could consolidate his power, and a series of ephemeral aspirants to the throne subsequently appeared and disappeared in Rohana without dislodging the Cholas from the north.[18] The crisis in the country left a scattering of turbulent chiefs and intractable rebels whose allegiance, if any, was at best opportunistic which proved a problem to both sides in the conflict, frustrating both the Sinhalese kings and the Cholas.Vijayabahu, from his base in Rohana, faced a similar difficulty; he had to contend with the hostility of local chiefs who regarded him as a greater threat to their independence than the Cholas were.Gradually the wider conflict developed into a prolonged, back-and-forth struggle of raids and counter-raids, with the forces of Vijayabahu advancing upon Polonnaruva and then falling back to fortresses in Dakkhinadesa and Rohana to withstand retaliatory Chola attacks and sieges.Vijayabahu eventually launched a successful two-pronged attack upon Anuradhapura and Polonnaruva, when he could finally establish a firm base in southern Sri Lanka.[18] Virarajendra Chola was forced to dispatch an expedition from the mainland to recapture the settlements in the north and carry the attack back into Rohana, in order to stave off total defeat.Polonnaruwa, a military outpost of the Sinhalese kingdom,[note 1] was renamed Jananathamangalam, after a title assumed by Rajaraja I, and become the new center of administration for the Cholas.When Sinhalese sovereignty was restored under Vijayabahu I, he crowned himself at Anuradhapura but continued to have his capital at Polonnaruwa for it being more central and made the task of controlling the turbulent province of Rohana much easier.
Vijayabahu I sent three armies to attack Polonnaruwa. One was sent along the western shore to Mahatittha and Polonnaruwa, another from the east across Magama, and the third and main force across Mahiyanga.