The Beatles and TS Eliot are among the artists to have been inspired by the Bhagavad Gita. Often called the "Bible of Hinduism," the poem has shaped Indian social, political and religious history for over 3,000 years. In the last of the series examining influential works of art, playwright Girish Karnad explores the Gita's impact and meaning. Used to support both war and peace, it became a talisman in the battle for Indian independence.