The older of the two madrasas overlooking the western flank of Registan Square was constructed after the death of Tamerlane (1417-20). The blue portal is flanked by two minarets that reach a height of 33m and is intended to evoke the night sky: it is covered with spirals and arabesques describing an ascent to the heavens against a backdrop of yellow and green ceramic stars. Over the decades the madrasa has remained the largest and most renowned of Central Asia's universities.