The Bengal Sultanate appointed Khan Jahan Ali, also known as Ulug Khan, as its governor in the Sundarbans in southern Bengal during the 15th-century. Ulugh Khan Jahan was a person of Turkic-origin. The title of "Ulugh" was common to rulers from the Turco-Persian tradition. The Bengal Sultanate attracted many immigrants from the Middle East and Central Asia, who brought with them ideas of Islamic architecture. Sufism was employed by Muslim missionaries to attract the local population. The high concentration of mosques suggests the rapidity with which the local population converted to Islam.