Ancient Kings of India, though adhered to Dharma, were quite adept in maintaining a well oiled Military force, always ready.
These forces, during peace time were engaged in building of water tanks and other social welfare activities.
Apart from the four or ix defined classes of forces, they had special forces like Velakkarapadai, Apaththudavi padai, which are loyal only to the King and performed the duties of a private army of the king much like the special protection detail of the US President.
They allo had a reserve Navy, especially the Cholas and Cheras while Pandyan had a Naval Army based on the exigencies.
Chaturangabala for organisation and Sadangabala for Administration, the fourfold force and sixfold control. In its shortened form it is called RathaGajaTuraPadai. In it, Ratha is the Chariot, Gajais the Elephant, Tura is the Horses And finally Padai is the Infantry. It is said that an army with a growing proportionate of the said forces y is a balanced and well composed one.
In Addition to the Divisions, there were other attached units in the Chola Army. Those are Nadapu – The Commissariat and Payanam – The Admiralty & Logistics. The addition of these new bureaucratic organisation inside the Army is What revolutionised the Chola Army resulting in victories of such a huge scale.