Bhagavad Gita is a very important and widely read and acclaimed book of spiritual wisdom coming under the group of scriptures known as Smritis.
Bhagavad Gita appears in the middle of the story of Mahabharata, around 2500 BCE. It is in the form of a discourse given by Lord Sri Krishna to Arjuna, one of the Pandavas, in the middle of a war field just before the beginning of epic war at Kurukshetra.