<P> Vijayalaya was the founder of the Imperial Chola dynasty which was the beginning of one of the most splendid empires in Indian history . Vijayalaya, possibly a feudatory of the Pallava dynasty, took an opportunity arising out of a conflict between the Pandya dynasty and Pallava dynasty in c. 850, captured Thanjavur from Muttarayar, and established the imperial line of the medieval Chola Dynasty . Thanjavur became the capital of the Imperial Chola Dynasty . </P> <P> The Chola dynasty was at the peak of its influence and power during the medieval period . Through their leadership and vision, Chola kings expanded their territory and influence . The second Chola King, Aditya I, caused the demise of the Pallava dynasty and defeated the Pandyan dynasty of Madurai in 885, occupied large parts of the Kannada country, and had marital ties with the Western Ganga dynasty . In 925, his son Parantaka I conquered Sri Lanka (known as Ilangai). Parantaka I also defeated the Rashtrakuta dynasty under Krishna II in the battle of Vallala . </P> <P> Rajaraja Chola I and Rajendra Chola I were the greatest rulers of the Chola dynasty, extending it beyond the traditional limits of a Tamil kingdom . At its peak, the Chola Empire stretched from the island of Sri Lanka in the south to the Godavari - Krishna river basin in the north, up to the Konkan coast in Bhatkal, the entire Malabar Coast in addition to Lakshadweep, Maldives, and vast areas of Chera country . Rajaraja Chola I was a ruler with inexhaustible energy, and he applied himself to the task of governance with the same zeal that he had shown in waging wars . He integrated his empire into a tight administrative grid under royal control, and at the same time strengthened local self - government . Therefore, he conducted a land survey in 1000 CE to effectively marshall the resources of his empire . He also built the Brihadeeswarar Temple in 1010 CE . </P> <P> Rajendra Chola I conquered Odisha and his armies continued to march further north and defeated the forces of the Pala Dynasty of Bengal and reached the Ganges river in north India . Rajendra Chola I built a new capital called Gangaikonda Cholapuram to celebrate his victories in northern India . Rajendra Chola I successfully invaded the Srivijaya kingdom in Southeast Asia which led to the decline of the empire there . This expedition had such a great impression to the Malay people of the medieval period that his name was mentioned in the corrupted form as Raja Chulan in the medieval Malay chronicle Sejarah Melayu . He also completed the conquest of the island of Sri Lanka and took the Sinhala king Mahinda V as a prisoner, in addition to his conquests of Rattapadi (territories of the Rashtrakutas, Chalukya country, Talakkad, and Kolar, where the Kolaramma temple still has his portrait statue) in Kannada country . Rajendra's territories included the area falling on the Ganges - Hooghly - Damodar basin, as well as Sri Lanka and Maldives . The kingdoms along the east coast of India up to the river Ganges acknowledged Chola suzerainty . Three diplomatic missions were sent to China in 1016, 1033, and 1077 . </P>

Who was considered the most powerful chola ruler
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