The Mahabharata and The Bhagavad Gita
Krishna had a role on both sides of the great war. He gave the Pandavs and the Kauravs each the option of having his army or having him but that he would not wield a weapon. The Kauravs chose his army and Arjun and the Pandavs chose him. Krishna took on the role of Arjun’s charioteer so he could be present on the field, but would not carry a weapon.
This is when Krishna recited the Bhagavad Gita, spoke about Dharma, Karma and doing what is right. He said it was just to battle the Kauravs due to their past evil deeds and to restore balance in the universe.
The Mahabharata and the Bhagavad Gita are both worthy of their own discussions, but for this article you just need to know that the Pandavs were victorious and all 100 cousins on the Kauravs side were killed in battle.
Krishna visited the Kauravs’ mother, Gandhari, to offer his condolences however she held him partly responsible for not bringing the war to an end sooner and knowingly allowing her children to die. She cursed him that within 36 years, the Yadav clan, which Krishna hails from, would be no more.