Sarathy (from Sanskrit saratha "one with a chariot" or "charioteer") is an epithet of Krishna (an Avatar of Vishnu). Krishna drove the chariot of Arjuna made the Pandavaas fight the war against adharma and kill the hundred Duryodhanas. It was only during this period, he preached the Hindu Bhagavad Gita. In reference to this, Krishna is also called Parthasarathi "Charioteer of Partha".
See also