The Cholas were one of the most dynamic and powerful kingdoms of the medieval south India. They were not only great administrators but also efficient expansionists. With the sheer strength of their armed or military forces, the Cholas were able to conquer Sri Lanka, Java and Sumatra. Their army consisted of elephants, cavalry and infantry. Also, the strongest men of the kingdom were selected to form the army. Training, discipline and cantonment were given prime attention. The commanders enjoyed the ranks of nayaka, senapati and mahadandanayaka.