 His forty-seven-year reign was chiefly marked by ambitious and corrupt dealings with the Tartar chiefs, and by his hazardous invocation of the Mongols, which ended his dynasty.His son, Az-Zahir, was Caliph for a short period before his death and An-Nasir's grandson, Al-Mustansir, was made caliph.Al-Mustansir founded the Mustansiriya Madrasah.