The war was fought for 18 long days.
The Kurukshetra War is a war described in the Indian epic Mahabharata as a conflict that arose from a dynastic succession struggle between two groups of cousins of an Indian kingdom called Kuru, the Kauravas and Pandavas, for the throne of Hastinapura. It involved a number of ancient kingdoms participating as allies of the rival groups.
The chapters (parvas) dealing with the war (from chapter six to ten) are considered amongst the oldest in the entire Mahabharat.