In the late Middle Ages, Pristina was an important town in Medieval Serbia and also the royal estate of Stefan Milutin, Stefan Uroš III, Stefan Dušan, Stefan Uroš V and Vuk Branković. Following the Ottoman conquest of the Balkans, Pristina became an important mining and trading center due to its strategic position near the rich mining town of Novo Brdo. The city was known for its trade fairs and items, such as goatskin and goat hair as well as gunpowder. The first mosque in Pristina was built in the late 14th century while under Serbian rule.