Map from late XIX century, representing a view about boundaries of Serbian empire during <a href="https://en.wikipedia.org/wiki/Stephen_Uro%C5%A1_IV_Du%C5%A1an_of_Serbia" class="extiw" title="en:Stephen Uroš IV Dušan of Serbia">Stefan Dušan</a>, about 1350. (Modern historiography has a stance that borders of Serbian empire were somewhat different. For the view of modern historiography, please see <a href="//commons.wikimedia.org/wiki/File:Dusanova_Srbija200.jpg" class="mw-redirect" title="File:Dusanova Srbija200.jpg">this map</a>.)
Gustav Droysen
Allgemeiner historischer Handatlas