 An Afghan fort (also known as Old Fort of Dhaka) was built at that time which was later converted to the present-form of Dhaka Central Jail in 1820 by the British.A 17th-century historian, Mirza Nathan, described the fort in his book Baharistan-i-Ghaibi as "surrounded by mud walls and the largest and strongest in pre-Mughal era".In 1412, Shah Ali Baghdadi, a saint arrived in Delhi and then came to Dhaka where he became a disciple of Shah Bahar of the Chistia order.