 Tarikh-i-Yamini, Rausat-us-Safa and Tarikh-i-Ferishtah speak of construction of mosques and schools and appointment of preachers and teachers by Mahmud and his successor Masud.Wherever Mahmud went, he insisted on the people to convert to Islam.The raids by Muhammad Ghori and his generals brought in thousands of slaves in the late 12th century, most of whom were compelled to convert as one of the preconditions of their freedom.