The name Kurukshetra applies to a circuit of about 128 kms. These plains of Haryana have provided a battle ground for ages. 21 battles were fought between Parashuram and the Kashtriya kings at Kurukeshtra. (@5,000 BCE) Then it was named Samant-panchak, as 5 lakes at battle field were filled with the blood of the slain warriors. The MB war (@ 3,000 BCE) that killed thosands of soilders was fought on the same soil. 60 kms to the South is Panipat. Three battles that changed the history of India were fought at Panipat. These battles claimed lives of thousands of soldiers and civilians.
Dhruturashtra calls Kurukeshtra the Dharma-keshtra. Where the Paandav and the Kaurav had assembled with an army of 18 Akshauhini.
King Region Army
Jayadrath Sindh, Sauver
Vind, Anuvind Avanti
Krutavarma Yadav King
Kekay Brothers Kekay
King Region Army
According to Adi Parva, Akshauhini is defined as:
About 2,000,000 infantry had gathered from India, Pakistan, and Afghanistan. Let's see the army maintained in the same area in later times. In 300 BCE Chandragupta Maurya's army was an incredibly large force of 700,000 men, 9,000 elephants, and 10,000 chariots. In Ashoka's time, the army consisted of 600,000 infantry, 130,000 cavalry, thousands of chariots and elephants. Still later in 16th century, Ibrahim Lodi, the sultan of Delhi, maintained an army of 100,000.
First battle of Panipat left 20,000 dead. Considering that as 10% of the fighting force, an army of about 200,000 was present in Panipat. Almost 100,000 people died in the third battle of Panipat. Considering that as 20% (high cause many died in this battle.) died in the battle, almost 500,000 people were present in Panipat.
About 700,000 to 100,000 infantry is seen in later times when the population in India was considerably more than the MB times. Thus a figure of 2,000,000 infantry (not including about 2 people per chariot, 3 people per elephant, 1 rider per horse, and supporting people like cooks, scouts, suppliers, care takers, doctors etc.) seems far fetched.
If we consider, akshauhiNi, anikini and chamu to be one and the same then the army size comes to:
These figures seem realistic. Many kings had sent 1 akshauhini force to help the Pandav / Kaurav. Kings of Sindh / Punjab / Bengal / Gujarat sending an infantary of about 3,000 is a possiblility that can be considered. (As against 10,000 infantry.)
MB mentions that ALL people died in the great war except: Ashwathama, Krupacharya, Krutavarma, Yuyutsu, Krishna, and the 5 Pandaav. I would rather take this to mean that ALL commanders, chiefs, and princes who had participated in the war died. Need not mean that EVERY soldier died. It has been seen in the Indian wars, that when ever the leader was killed, his soilders would run helter skelter. Such scenes are described in the MB war too. Thus killing the leader would probably be the same as death of his whole team. And maybe hence the description. Even the references such as Bheeshma, Bheem, Arjun, Abhimanyu etc. killed x akshauhini on nth day, seems to mean the same. It could mean that they killed the leaders of those many units on the particular days.
There is a reference to the Naraayaniya army that had vowed to kill or die in the war. This explicitly means that they did not have the option to leave the battlefield. Implying that all others had the option.
The weapons used in the war were not mass destructive. Irrespective of the fact that many people put forth, and MB mentions, that tens of thousands of people were killed by the single use of a weapon. Weapons such as arrows, spears, swords, maces etc, can kill only one person at a time. That too, only if the weapon hits fatally. Thus after ALL the leaders of one side were killed, the war was over. We can assume that the number of people killed in the war was say around 5% of the force. All these people belonged to different geographical areas and thus these areas were not severely affected by the war or the loss of people in the war. The most affected regions remained the Kuru and the Panchal.