Ashwatthama was the son of guru Dronacharya and he is the grandson of the Brahmin sage Bharadwaja. Ashwatthama is a mighty who fought on the Kaurava side against the Pandavas.
Ashwatthama is the avatar of one of the eleven Rudras and he is one of the seven Chiranjivi. Along with his maternal uncle Kripa, Ashwatthama is believed to be a living survivor of the Kurukshetra War.The rumours about his death led to the death of Dronacharya .
The final commander-in-chief of the Kauravas, Ashwatthama slaughters many in the Pandava camp in a sneak attack. Ashwatthama was the son of Dronacharya and Kripi. Drona did many years of severe penance to please Lord Shiva in order to obtain a son who possesses the same valiance as Lord Shiva. Ashwatthama was born to become a Chiranjivi and cannot be killed by any kind of weapons. Ashwatthama was born with a gem in his forehead which gives him power over all living beings lower than humans; it protected him from hunger, thirst and fatigue.
The Pandavas and Krishna who were away during night, now returned to their camp the next day morning. Hearing the news of these events in the morning Yudhishthira fainted and the Pandavas become inconsolable. The Pandavas went searching for Ashwatthama to sage Vyasa’s ashram. On seeing the approaching angered Pandavas, Ashwatthama as a last resort, devised a Brahmashirsha astra from a blade of grass and invoked it against the Pandavas and Krishna. Arjuna invokes the same astra, which he received by Drona itself, towards Ashwatthama.
On seeing the two powerful astra’s heading for a head on cataclysmic (catastrophic) collision that would result in the total annihilation of the entire Earth, Vyasa stopped these divine weapons from colliding with each other by using his yogic power. He asked both these warriors to withdraw their respective weapons. Arjuna was able to withdraw his Brahmashirsha astra, while Ashwatthama could not do so as Drona did not teach his son how to withdraw it, thus limiting the power of Ashwatthama to use the astra for only one instance. Ashwatthama was given the option of deviating his weapon towards and uninhabited place, so that the astra could explode harmlessly. Out of rage, Ashwatthama instead directed the weapon towards the womb of the pregnant Uttara in an attempt to end the lineage of the Pandavas. The angered Pandavas want to kill Ashwatthama, but Sage Vyasa reminded them of the deceitful tactics they had used against the Kauravas.
As punishment, Ashwatthama was asked to surrender the gem on his forehead. Disgusted, Krishna then cursed Ashwatthama that for 3,000 years he will roam in the forests with blood and puss oozing out of his injuries and cry for death. Since he had no fear of death during war, death would not meet him. He will have neither any hospitality nor any accommodation; he will be in total isolation without any contact of physical communication from mankind and society. The wound caused by the removal of this gem on his forehead will not heal and his body will suffer from a host of incurable diseases forming sores and ulcers that would never heal for 3000 years”