 Mirza Nathan's eyewitness accounts have provided detailed and lucid accounts of the Mughal conquest of Kamarupa, Kachhar and Assam.The accounts of the several Magh invasions of the Mughal territory of Bhulua and the several Mughal invasions to Chittagong are found in greater details in the Bharistan; the Arakanese and the Portuguese sources give only a short account.The "Baharistan-i-Ghaibi" was lost for a long time until its discovery by Sir Jadunath Sarkar in the national library in Paris, France.