Rajendra Chola (Civ6)/Civilopedia

Not only did Rajendra I, the great Chola king, extend the influence of his already vast empire to the banks of the River Ganges, but across the ocean to coastal Burma, the Andaman and Nicobar islands, Sri Lanka, and the Maldives. And he led a great navy to defeat and plunder the kingdom of the Srivijaya (Sumatra, Java and Malaya), and extracted tribute from the Khmer kingdom of Cambodia.
Born heir to Rajaraja I, Rajendra was made co-regent of the Chola Empire in 1012 AD and formally ascended the throne in 1014. He took a hands-on approach to conquering his neighbors, leading campaigns to the north to defeat the Karnataka, the Western Chalukya and Mahipala, the Pala king of Bengal and Bihar. To complete the task begun by his father, Rajendra led an amphibious invasion of Sri Lanka in 1018, wreaking havoc and overthrowing the ruling Sinhala dynasty.
But his greatest achievement may have been leading the Chola navy in sailing across the open waters of the Indian Ocean (an unheard of feat at the time) to attack the wealthy Indonesian Srivijayan kingdoms in 1025. The Srivijayans had dominated the trade routes around the islands and Malaysia for a century or more with their fleets, but had clashed with the expanding Khmer when the Tambralinga king allied with the Srivijayans. The Khmer, having no ships, called upon fellow Hindu Rajendra, who was only too happy to end the Srivijayan control of the seas. In a brilliant series of battles and raids, he sacked their coastal ports and capitals, sending the Indonesian empire into a downward spiral from which it never recovered.
Following a return in 1041 to Sri Lanka to put down a revolt by those unhappy with the benefits of Chola civilization, Rajendra I died in 1044.