Timur initiated the last flowering of Mawarannahr by gathering in his capital, Samarkand, numerous artisans and scholars from the lands he had conquered. By supporting such people, Timur imbued his empire with a very rich Perso-Islamic culture. During Timur's reign and the reigns of his immediate descendants, a wide range of religious and palatial construction projects were undertaken in Samarkand and other population centers. Timur also patronized scientists and artists; his grandson Ulugh Beg was one of the world's first great astronomers. It was during the Timurid dynasty that Turkic, in the form of the Chaghatai dialect, became a literary language in its own right in Mawarannahr, although the Timurids were Persianate in nature. The greatest Chaghataid writer, Ali Shir Nava'i, was active in the city of Herat, now in northwestern Afghanistan, in the second half of the 15th century.