|This article does not cite any references or sources. (January 2013)|
The Chakravyūha or Padmavyūha, is a multi-tier defensive formation that looks like a blooming lotus (padma, पद्म) or disc (chakra, चक्र) when viewed from above. The warriors at each interleaving position would be in an increasingly tough position to fight. The formation was used in the battle of Kurukshetra by Dronacharya, who became commander-in-chief of the Kaurava army after the fall of Bhishma Pitamaha.
The various vyūhas (military formations) were studied by the Kauravas and Pandavas alike. Most of them can be beaten using a counter-measure targeted specifically against that formation. It is important to observe that in the form of battle described in Mahabharata, it was important to place the powerful fighters in those positions where they could inflict the maximum damage to the opposing force, or defend their own side.
Abhimanyu and the Chakravyūha
The Chakravyūha or Padmavyūha was a 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 at the most-famous occasion of its use. Because he had never learnt to escape the formation, he was trapped upon entry and fought alone. After Abhimanyu had penetrated the sixth tier of the formation, all the Kauravas' commanders attacked him simultaneously, against the customary rules of Dharmayuddha, and gradually exhausted and killed him.
The rotating-circles-within-circles is a poetic concept, promoted over the years without any study of military history, any commentary by military officers, or even without actually trying such a formation and seeing the effects.
It is impossible to execute such a formation during an actual fight even with 10 people on foot, let alone divisions including infantry, cavalry, chariots, and elephants.
Anyone who is seriously interested in verifying the rotating-circles-within-circles myth can try making such two circles of say 10 men in each circle and try rotating them within each other while being attacked by another 10 people from outside. Toy bows and arrows and toy swords can be employed so that no one gets seriously injured.
Within 10-15 minutes the myth of rotating-circles-within-circles will disappear.
This is the very reason that such a supposedly "great military formation" (rotating-circles-within-circles) was never used in any recorded battles. Possible basis appears in a classic military maneuver, wherein a numerically superior force lures in and encircles a smaller force. With the 2-3-2 arrangement, this formation also looks like the outline of a blooming flower when seen from outside – hence the name of 'padmavyuha'.
This formation, keeping the front fixed while enveloping the enemy on both sides, has been widely used over last many centuries by armies all over the world, ranging from the Battle of Cannae in 216 B.C. to the siege at Stalingrad in November 1942. In similar formations, the inward ring attacks the enemy whereas the outward ring prevents relief efforts.