What made Chola administration strong and effective?

Chola administration was very well organised and efficient. It can be summarized as below:

1. Nadu: It was a land unit comprising of many villages of ur (peasants) who practiced irrigation agriculture.

2. Rich landowners: Castes like Vellala supervised Nadu under the central Chola government. They were given titles like Araiyar by the king and various offices in the state to manage.

3. Brahmadeya: These were huge land settlements of Brahmanas in the south who received land grants from the king.

4. Sabha of Brahmana: This was the group of prominent Brahmana landholders who looked after the Brahmadeyas.

5. Nagarams: These were the association of traders who also carried out administrative work in towns sometimes.

Apart from that, they possessed an efficient army and navy. A powerful bureaucracy assisted the king in the tasks of administration and in executing the orders of the King.