 The "Baharistan-i-Ghaibi" is a unique and extensively documented source of the history of contemporary Bengal, Bihar and Assam and the Mughal subjugation of the region.The only other source of the time Tuzk-e-Jahangiri, the official memoirs of the emperor only briefly mention a few events in Bengal.Mirza Nathan's account follows the campaigns of Islam Khan, as well as the conquest of Kamarupa, Tippera, Kachhar, Assam and Chittagong in lucid and copious details, including full accounts of the battles, the political situation and socio-economic life and conditions of the region during Jahangir's time.