Inscriptions and historical sources assert that the Medieval Chola king Rajendra Chola I sent a naval expedition to Indochina, the Malay Peninsula and Indonesia in 1025 in order to subdue Srivijaya. The Thiruvalangadu plates, the Leyden grant, and the Tamil stele of Rajendra Chola I are the principal sources of information about the campaign.
The most detailed source of information on the campaign is the Tamil stele of Rajendra Chola I. The stele states:
(Who) having despatched many ships in the midst of the rolling sea and having caught Sangrāma-vijayōttunga-varman, the king of Kadāram, together with the elephants in his glorious army, (took) the large heap of treasures, which (that king) had rightfully accumulated; (captured) with noise the (arch called) Vidhyādharatorana at the "war gate" of his extensive city, Śrī Vijaya with the "jewelled wicket-gate" adorned with great splendour and the "gate of large jewels"; Paṇṇai with water in its bathing ghats; the ancient Malaiyūr with the strong mountain for its rampart; Māyuriḍingam, surrounded by the deep sea (as) by a moat; Ilangāśōka (i.e. Lankāśōka) undaunted in fierce battles; Māpappālam having abundant (deep) water as defence; Mēviḷimbangam having fine walls as defence; Vaḷaippandūru having Viḷappandūru (?); Talaittakkōlam praised by great men (versed in) the sciences; Mādamālingam, firm in great and fierce battles; Ilāmuridēśam, whose fierce strength rose in war; Mānakkavāram, in whose extensive flower gardens honey was collecting; and Kadāram, of fierce strength, which was protected by the deep sea
The Thiruvalangadu plates, from the fourteenth year of Rajendra Chola I, mentions his conquest of Kadaram but does not go into the details. The first attempt by someone from outside India to identify the places associated with the campaign was made by epigraphist E. Hultzsch, who had published the stele in 1891. Hultzsch identified the principalities mentioned in the inscription with places ruled by the Pandyan Dynasty. In 1903, he rescinded his theory and stated that the stele described Rajendra Chola I's conquest of Bago in Burma.George Coedès' Le Royaume de Sri Vijaya published in 1918 after several years of research, rejected both the theories and provided the first convincing description of Rajendra Chola I's conquest of Southeast Asia.