No references to Krishna except the above have been found in the earlier Upanishads and Sutras.  He is not mentioned in Manu but in one aspect or another he is the principal figure in the Mahabharata, yet not exactly the hero.  The Ramayana would have no plot without Rama, but the story of the Mahabharata would not lose its unity if Krishna were omitted.  He takes the side of the Pandavas, and is sometimes a chief sometimes a god but he is not essential to the action of the epic.

The legend represents him as the son of Vasudeva, who belonged to the Sattvata sept[374] of the Yadava tribe, and of his wife Devaki.  It had been predicted to Kamsa, king of Mathura (Muttra), that one of her sons would kill him.  He therefore slew her first six children:  the seventh, Balarama, who is often counted as an incarnation of Vishnu, was transferred by divine intervention to the womb of Rohini.  Krishna, the eighth, escaped by more natural methods.  His father was able to give him into the charge of Nanda, a herdsman, and his wife Yasoda who brought him up at Gokula and Vrindavana.  Here his youth was passed in sporting with the Gopis or milk-maids, of whom he is said to have married a thousand.  He had time, however, to perform acts of heroism, and after killing Kamsa, he transported the inhabitants of Mathura to the city of Dvaraka which he had built on the coast of Gujarat.  He became king of the Yadavas and continued his mission of clearing the earth of tyrants and monsters.  In the struggle between the Pandavas and the sons of Dhritarashtra he championed the cause of the former, and after the conclusion of the war retired to Dvaraka.  Internecine conflict broke out among the Yadavas and annihilated the race.  Krishna himself withdrew to the forest and was killed by a hunter called Jaras (old age) who shot him supposing him to be a deer.

In the Mahabharata and several Puranas this bare outline is distended with a plethora of miraculous incident remarkable even in Indian literature, and almost all possible forms of divine and human activity are attributed to this many-sided figure.  We may indeed suspect that his personality is dual even in the simplest form of the legend for the scene changes from Mathura to Dvaraka, and his character is not quite the same in the two regions.  It is probable that an ancient military hero of the west has been combined with a deity or perhaps more than one deity.  The pile of story, sentiment and theology which ages have heaped up round Krishna’s name, represents him in three principal aspects.  Firstly, he is a warrior who destroys the powers of evil.  Secondly, he is associated with love in all its forms, ranging from amorous sport to the love of God in the most spiritual and mystical sense.  Thirdly, he is not only a deity, but he actually becomes God in the European and also in the pantheistic acceptation of the word, and is the centre of a philosophic theology.