Chola Empire was a Tamil empire which was one of the longer-ruling dynasties in southern India. The earliest datable references to this Tamil dynasty are in inscriptions from the 3rd century BC left by Asoka, of Maurya Empire; as one of the Three Crowned Kings, the dynasty continued to govern over varying territory until the 13th century AD.
The heartland of the Cholas was the fertile valley of the Kaveri River, but they ruled a significantly larger area at the height of their power from the later half of the 9th century till the beginning of the 13th century. The whole country south of the Tungabhadra was united and held as one state for a period of two centuries and more. Under Rajaraja Chola I and his son Rajendra Chola I, the dynasty became a military, economic and cultural power in South Asia and South-East Asia. The power of the new empire was proclaimed to the eastern world by the expedition to the Ganges which Rajendra Chola I undertook and by the occupation of cities of the maritime empire of Srivijaya, as well as by the repeated embassies to China.