The art and science of warfare was highly developed in ancient India, if the accounts of war given in the Rāmāyaṇa and the Mahābhārata are to be believed.
Weapons used were divided into two broad categories: astras and śastras. Astras were missiles discharged from their sources like the bow. Śastras were weapons used by directly holding them in hand. Arrows, discuses and spears belong to the first, whereas swords belong to the second category.
By far, the most powerful of all the astras often mentioned in the epics and the mythological lore is the Brahmāstra also called ‘Brahmaśirostra’. Śiva is said to have given it to the sage Agastya. Agastya gave it to Agniveśa who gave it to Droṇa. Arjuna got it from Droṇa.
According to another version, Brahmā the creator specially made it for Devendra. The sage Agastya who got it in course of time, handed it over to Śrī Rāma.
It is more likely that the Brahmāstra was not a particular missile physically existent, but a terrible power that could be invoked into any missile by the appropriate mantras. Its use was restric-ted to extraordinary situations and when the enemy was not an ordinary human being.
Śrī Rāma is reputed to have killed Rāvaṇa with this Brahmāstra.