The Gita is the linchpin of a great epic, and that epic is the Mahabharata, or Great Story of the Bharatas. With nearly one hundred thousand verses divided into eighteen books, it is one of the longest epic poems in the world-fully seven times longer than the Iliad and the Odyssey combined, or three times longer than the Bible. It is in fact a whole library of stories that exerted a tremendous influence on the people and literature of India.
The central story of the Mahabharata is a conflict over succession to the throne of Hastinapura, a kingdom just north of modern Delhi that was the ancestral realm of a tribe most commonly known as the Bharatas. (India was at that time divided amongst many small, and often warring, kingdoms.)
The struggle is between two groups of cousins, the Pandavas or sons of Pandu, and the Kauravas, or descendants of Kuru. Because of his blindness, Dhritarashtra, the elder brother of Pandu, is passed over as king, the throne going instead to Pandu.