In the course of the 14th and 15th centuries, Pristina developed as an important mining and trading center thanks to its proximity to the rich mining town of Novo Brdo, and due to its position of the Balkan trade routes. The old town stretching out between the Vellusha and Prishtevka rivers which are both covered over today, became an important crafts and trade center. Pristina was famous for its annual trade fairs (''Panair'') and its goat hide and goat hair articles. Around 50 different crafts were practiced from tanning to leather dying, belt making and silk weaving, as well as crafts related to the military – armorers, smiths, and saddle makers. As early as 1485, Pristina artisans also started producing gunpowder. Trade was thriving and there was a growing colony of Ragusan traders (from modern day Dubrovnik) providing the link between Pristina's craftsmen and the outside world. The first mosque was constructed in the late 14th century while still under Serbian rule. The 1487 defter recorded 412 Christian and 94 Muslim households in Pristina, which at the time was administratively part of the Sanjak of Vučitrn.