Flag of the Second Bulgarian Empire over Varna on a portolan map by Guillem Soler, dated 1385.
Guillem Soler
1385
Bibliotheque Nationale de Fance <a rel="nofollow" class="external free" href="https://gallica.bnf.fr/ark:/12148/btv1b530648817/f1.item.r=carte%20nautique.zoom">https://gallica.bnf.fr/ark:/12148/btv1b530648817/f1.item.r=carte%20nautique.zoom</a>