The two most important Tamil kings (maybe the term "emperors" is more appropriate) were: - Raja Raja Chola I - Rajendra Chola I (son of the former) The first established the Chola empire, the second achieved even more power for the Chola empire. 1) "Rajaraja Chola I (Tamil: இராசராச சோழன் born as Arulmozhi Varman) is one of the greatest emperors of the Tamil Chola Empire and India, who ruled between 985 and 1014 CE. He established the Chola empire by conquering the kingdoms of southern India expanding the Chola Empire as far as Sri Lanka in the south, and Kalinga (Orissa) in the northeast. He fought many battles with the Chalukyas in the north and the Pandyas in the south. By conquering Vengi, Rajaraja laid the foundations for the Later Chola dynasty. He invaded Sri Lanka and started a century-long Chola occupation of the island. Rajaraja Chola I holds the distinction of being one of the six Indian Kings who never lost out on the battlefield to the enemies. His great warrior son Rajendra Chola is also one among that exclusive league. He streamlined the administrative system with the division of the country into various districts and by standardizing revenue collection through systematic land surveys. He built the magnificent Brihadisvara Temple in Thanjavur and through it enabled wealth distribution amongst his subjects. His successes enabled his son Rajendra Chola I to extend the empire even further." Source and further information: http://en.wikipedia.org/wiki/Raja_Raja_Chola_I 2) "Rajendra Chola I (Tamil: முதலாம் இராசேந்திர சோழன்) was the son of Rajaraja Chola I, the great Chola king of present day southern India. He succeeded his father in 1014 C.E. as the Chola emperor. During his reign, he extended the influences of the already vast Chola empire up to the banks of the river Ganges in the north and across the ocean. Rajendra’s territories extended coastal Burma, the Andaman and Nicobar Islands, Lakshadweep, Maldives, conquered the kings of Srivijaya (Sumatra, Java and Malaya in South East Asia) and Pegu islands with his fleet of ships. He defeated Mahipala, the Pala king of Bengal and Bihar, and to commemorate his victory he built a new capital called Gangaikonda Cholapuram. Tamil Chola armies exacted tribute from Thailand and the Khmer kingdom of Cambodia. Like the predecessors of the Cholas, the Pallavas and the contemporaneous Pandiyans, the Cholas too under Raja Raja I the father of Rajendra and then Rajendra Chola I too undertook several expeditions to occupy territories outside Indian shores. Of these kings, it was Rajendra who made extensive overseas conquests of territories like the Andamans, Lakshadweepa, wide areas Indo China (Thailand, Malaysia, Laos, Indonesia and Modern Vietnam) and indeed, Burma (**). In fact, Rajendra Chola I was the first Indian king to take his armies overseas and make conquests of these territories, even though there is epigraphical evidence of Pallava presence in these very areas, but it is not known that Burma and Indo-China were subordinate to them, as they were under Rajendra and his successors up to Kulothunga I(**). But these were benevolent conquests, as they seem to hve been during the times of the Pallavas, with there being wide cultural inter-changes, and the influence of the Pallavas and Cholas in the architecture in those areas in both Buddhist and Hindu religious centres showing remarkable similarities(**). He also built a temple for Siva at Gangaikonda Cholapuram, similar in design to the Tanjore Brihadisvara temple built by Rajaraja Chola. He assumed titles Parakesari and Yuddhamalla." Source and further information: http://en.wikipedia.org/wiki/Rajendra_Chola_I