The historicity of the Kurukshetra War is unclear. Many historians estimate the date of the Kurukshetra war to Iron Age India of the 10th century BCE. The setting of the epic has a historical precedent in Iron Age (Vedic) India, where the Kuru kingdom was the center of political power during roughly 1200 to 800 BCE. A dynastic conflict of the period could have been the inspiration for the Jaya, the foundation on which the Mahābhārata corpus was built, with a climactic battle eventually coming to be viewed as an epochal event.
Puranic literature presents genealogical lists associated with the Mahābhārata narrative. The evidence of the Puranas is of two kinds. Of the first kind, there is the direct statement that there were 1015 (or 1050) years between the birth of Parikshit (Arjuna's grandson) and the accession of Mahapadma Nanda (400-329 BCE), which would yield an estimate of about 1400 BCE for the Bharata battle. However, this would imply improbably long reigns on average for the kings listed in the genealogies. Of the second kind are analyses of parallel genealogies in the Puranas between the times of Adhisimakrishna (Parikshit's great-grandson) and Mahapadma Nanda. Pargiter accordingly estimated 26 generations by averaging 10 different dynastic lists and, assuming 18 years for the average duration of a reign, arrived at an estimate of 850 BCE for Adhisimakrishna, and thus approximately 950 BCE for the Bharata battle.
B. B. Lal used the same approach with a more conservative assumption of the average reign to estimate a date of 836 BCE, and correlated this with archaeological evidence from Painted Grey Ware (PGW) sites, the association being strong between PGW artifacts and places mentioned in the epic. John Keay confirms this and also gives 950 BCE for the Bharata battle.
Attempts to date the events using methods of archaeoastronomy have produced, depending on which passages are chosen and how they are interpreted, estimates ranging from the late 4th to the mid-2nd millennium BCE. The late 4th-millennium date has a precedent in the calculation of the Kaliyuga epoch, based on planetary conjunctions, by Aryabhata (6th century). Aryabhata's date of 18 February 3102 BCE for Mahābhārata war has become widespread in Indian tradition. Some sources mark this as the disappearance of Krishna from earth. The Aihole inscription of Pulikeshi II, dated to Saka 556 = 634 CE, claims that 3735 years have elapsed since the Bharata battle, putting the date of Mahābhārata war at 3137 BCE. Another traditional school of astronomers and historians, represented by Vriddha-Garga, Varahamihira (author of the Brhatsamhita) and Kalhana (author of the Rajatarangini), place the Bharata war 653 years after the Kaliyuga epoch, corresponding to 2449 BCE.