Chandragupta and Chanakya learnt lessons from these mistakes. They now stationed troops in the conquered regions so those enemies would not rise and cause any trouble. Chanakya with his cleverness had earlier won the friendship of King Parvataka (or Porus Second). Now Parvataka, his brother Vairochaka and son Malayaketu came with their armies to help them.

The Nanda king had the support of a big army. The other equally important support was the guidance of his very able minister, Amatya Rakshasa. This minister was very intelligent and had unlimited loyalty to the king. Chanakya knew that defeating Amatya Rakshasa was as important and necessary as vanquishing Nanda's army.

Chanakya told his friend Indusharma, "My dear friend, you must disguise yourself and be in the company of Amatya Rakshasa. Pretend to be a friend and be his astrologer. Change your name to Jeevasiddhi. Keep me informed of all developments there through your disciples very carefully. Your help is very necessary for me to destroy the Nandas. And be very cautious."

So he sent Indusharma to Amatya Rakshasa. Disciples of Indusharma- Vegasharma, Siddhartha and Masopavasi also took up jobs under Amatya Rakshasa and under army officers.

The Nandas and Amatya Rakshasa made all preparations to face the attack of Chandragupta and Chanakya.

Details are not clearly known regarding the war between the Nandas on the one hand and Chandragupta and Chanakya on the other. But it was a keen and bitter fight. The Nanda king died. His sons and relatives also died.Even Amatya Rakshasa became helpless. Chandragupta was victorious. The only survivor was Sarvartha- siddhi, the father of the Nandas. He was very old. "I do not want anything. I will go to the forest for meditation. Please permit me," he begged. Chanakya and Chandragupta agreed.