Under the king Rajaraja Chola I and Rajendra Chola I, the empire became powerful in the field of army, finance and culture in South Asia and South-east Asia. Raja Raja Chola (985-1014 AD) was the greatest ruler of this dynasty. He first destroyed Chera (the rulers of Kerala, south India) navy at Trivendrum, then captured Madura and subsequently defeated Sinhalese (Shri Lankan) king Mahendra V thus occupying northern Cylon (modern Shri lanka). He further went ahead and conquered Maldive islands. His son Rajendra Chola (1012-1044 AD) was very worthy successor. He expanded his inherited empire by occupying whole of Shri Lanka (1018 AD) and later crowning the glory by inflicting a crushing defeat on Shrivijaya, the King of Indonesia, in 1025 AD. His empire consisted of whole of southern India, Sri Lanka, and parts of the Malay peninsula (modern Malysia) and the Sumatran-based Srivijaya Kindgom (modern Indonesia).
After that Rajaraja Chola I and Rajendra Chola I the two great king of the dynasty, expanded the kingdom outside the traditional limits of a Tamil State, from the Sri Lankan island in the south to the Godavari-Krishna River basin in the north with the Konkan coast in Bhatkal, the total Malabar Coast including Lakshadweep, Maldives and huge range of Chera Empire. The Cholas had a good architectural sense and it is found today in different place of south India. They built a number of Siva temples alongside the banks of the river Kaveri. The Airavateswara temple at Darasuram is a traditional example of Chola art and architecture. Rajaraja Chola and his son Rajendra Chola I had established two temples in Thanjavur and Gangaikondacholapuram. The superb Siva temple of Thanjavur was completed around 1009 AD; it was a great achievement of the time of Rajaraja. The largest and tallest of all Indian temples of its time was the temple of Gangaikondacholisvaram which was created by Rajendra Chola in around 1030 AD. During the reign from 850 AD to 1200 AD was the golden age of Tamil culture basically on literature. Many great Hindu, Jain and Buddhist writers flourished in this time. Jivaka-chintamani by Tirutakkatevar and Sulamani by Tolamoli are two great books by non-Hindu writer. The great Hindu writer Kamban flourished during the reign of Kulothunga Chola III. His Ramavatharam is a great epic in Tamil literature was translating version of the Sanskrit epic Ramayna into Tamil language. Jayamkondar's masterwork Kalingattuparani is an example of narrative poetry. This explains the events during Kulothunga Chola I's war in Kalinga. The famous Tamil poet Ottakuttan served at the courts of three of Kulothunga's successors written by Kulothunga Cholan Ula.