Rajaraja began his first campaign in the eighth year of his reign. The Pandyas, Cheras and the Sinhalas allied against the Cholas. In 994 AD, Rajaraja destroyed the fleet of the Chera king Bhaskara Ravi Varman Thiruvadi (c. 978–1036 AD) in the Kandalur War. Rajaraja defeated the Pandya king Amarabhujanga and captured the port of Virinam. To commemorate these conquests, Rajaraja assumed the title Mummudi Chola, a title used by Tamil kings who ruled the three kingdoms of Cholas, Pandyas and Cheras. In 1008 AD, Rajaraja captured Udagai from Cheras and Rajendra Chola I led the Chola army in this battle.
Due to Rajaraja's Desire to record his military achievements, he recorded the important events of his life in stones. An inscription in Tamil from Mulbagal in Karnataka shows his accomplishments as early as the 19th year. An excerpt from such a Meikeerthi, an inscription recording great accomplishments, follows: