Vijayalaya, who belonged to the ancient chiefly family of the cholas of the from Uraiyur, defeated Muttaraiyar (a minor chiefly family that held power in Kaveri delta) and capture Kaveri delta inthe middle of ninth century. The successors of Vijayalaya conquered neighbouring regions and the kingdom grew in size and power. The Pandayan and Pallava territories to he south and north were made part of this kingdom. Rajaraja I expanded control over most these areas. his son rajendra I raided the Ganga valley, Sri Lanka and countries of southeast Asia, developing a navy for these expeditions.