who knew how to get out of chakravyuh
Padmavyuha The Chakravyūha or Padmavyūha was a very special formation (vyuha), and knowledge of how to penetrate it was limited to only a handful of warriors on the Pandavas' side, namely: Abhimanyu, Arjuna, Krishna and Pradyumna, of which only Abhimanyu was present when the Kauravas used it on the battlefield. In the Mahabharata it is mentioned that Abhimanyu learnt about the Chakravyūha while in his mother's womb but he was not able to hear how to escape the formation. After Abhimanyu had penetrated the sixth tier of the formation, all the Kauravas' commanders attacked him simultaneously, which was against the righteous rules of warfare Dharmayuddha, and gradually exhausted and killed him.[2]
Magadha Accounts differ slightly as to the cause of King Ajatashatru's war with the Licchavi, an area north of the river Ganges. It appears that Ajatashatru sent a minister to the area who worked for three years to undermine the unity of the Licchavis. To launch his attack across the Ganges River, Ajatashatru built a fort at the town of Pataliputra. Torn by disagreements the Licchavis fought with Ajatashatru. It took fifteen years for Ajatashatru to defeat them. Jain texts tell how Ajatashatru used two new weapons: a catapult, and a covered chariot with swinging mace that has been compared to a modern tank. Pataliputra began to grow as a centre of commerce and became the capital of Magadha after Ajatashatru's death.