The fact and the extent of his conquest are known from his inscriptions. Towards the end of his reign, or before his death , the Rashtrakutas under Krishnaraja III invaded the Tamil Country, killed the Chola Prince Rajadityan at Takkolam (near Arakonam) in AD 947-948, and seized Tondainadu which they seemed to have ruled for about a quarter of a century, confining the sway of the Cholas to their ancestral dominion comprising the Thanjavur and Trichy districts.
The names of the next five kings after Rajaditya are known, but little is on record regarding their life history. They were Gandaraditya, Arinjaya, Parantakan II, Aditya Karikala or Aditya II and Madurantaka. Aditya Karikala II appears to have re-conquered Tondainadu a few years later.On Aditya's death, or on the death of Parantakan II, whichever was the later, the succession was probably disputed. The subject besought, Arunmolivarman (Rajarajan) to become the King, but he did not want the throne as long as his paternal uncle Madurantak Uttama Cholan was fond of the crown. Eventually, Arunmolivarman was appointed heir-apparent. Rajarajan became the king in 985 AD. His reign was the starting point of a period of unexampled prosperity.
Rajarajan began his career by the conquest of the Chera country. He defeated Chera King Bhaskara Ravivarman, whose fleet he destroyed i
n
the port of Kandalur. He also seized Pandya Amara Bhujanga and captured
the
port of Vilinam. By his campaign against the Singhalees he annexed
northern Ceylon, building a number of stone temple in the Ceylonese
capital Polonnaruva, of which one now stands to Shiva. It was at
about the 14th year of his reign (AD 998-999) that most of his
triumphs were achieved. He conquered the Gangas of Mysore(capital at
Talakad),
the country of Nolambas (Bellary and Eastern Mysore), Tadigaipadi
(the district of Mysore), vengi (southern part of Northern Circars),
Coorg (kudamalainadu) and the Pandyas. The last were the natural
enemies of Cholas. Having already overcome the Chera, Rajarajan
assumed the title "Mummudi Cholan". The Western and the Eastern
Chalukyas of the Deccan were conquered next.
A few year later the
Eastern Chalukya prince Vimaladitya married the eldest daughter
of Rajarajan and became the King of Vengi, which was still under Cholas.
his son and grandson also married daughters of Chola kings, and
it
was the second of these rulers, the great Kulotunga I, who, in
later years, claimed the Chola Kingdom as his mother heritage and established
a new dynasty at Thanjavur. The Western Chalukyas remained for
the
long the stubborn enemies of the Cholas. During the next three
years, Rajarajan subdued Quilon and the northern kingdom of Kalinga,
through
his son Rajendra Cholan. Chola also simultaneously directed his
arms against Ceylon. Rajarajan moved the capital from Anuradhapura
to
Polonnaruva and built here in memory of his mother Vanavan Mahadevi
the Siva Devalaya for Vanavan Mahadevi Isvaramudaiyar. With Rajarajan,
the Chola culture and Saiva religion permeated the whole of Ceylon.
Rajarajan
having thus realised his cherished military glories, in or about
1003 AD has sheathed his sword, and turned his thoughts towards
a life of peace. It was about this time, that the Chidambaram temple
authorities bestowed on him the title of "Sri Rajarajan" and "Sivapadasekara.
As a worshiper of Sri Thyagaraja at Thiruvarur, the king heard the recital of the holy presence, that remained the current collection of the Thevaram hymns of Saint Sundarar, Thirunavukkarasar and Jnanasambandar. King concerned about the loss of priceless Saiva devotional treasure, and set out for their search.He sought Adi-Saiva Nambiandar-Nambi of Thirunaraiyar's help and discovered the collection of the Thevaram - Divine garland of hymns- in a room at the back of the Sri Nataraja's sanctum at the Chidambaram temple. At the instance of the king, Nambiandar-Nambi compiled them and Rajaraja arranged to have them sung in the Saiva shrines.