1395. In 1404, King Ostoja gave Duvno and Glamoč to Duke Pavle Klešić. In 1444 or earlier, Duvno became a possession of Stjepan Vukčić Kosača, the duke of the Duchy of Saint Sava. Ottoman Empire The Ottomans took advantage of the rivalry between Croatian nobles and entered parts of Bosnia in the 1430s. They first passed through the area of Tomislavgrad in 1449 on the way to Cetina, ie the area controlled by Croatian Ban Petar Talovac, at the invitation of Stjepan Vukčić Kosača. Namely, Kosača called on the Ottomans against Duke Sladoje Semković. During their campaign, the Ottomans took slaves and looted the country. After completely conquering Bosnia in 1463, the Ottomans turned to Herzegovina. Between 1468 and 1469, the area of Završje – Glamoč, Livno, and Tomislavgrad – completely fell under Ottoman rule. The Ottomans founded the Sanjak of Herzegovina in 1470, while the Kaza of Drina, a subdivision of that sanjak in 1477 included the nahiyahs Drežnica, Ljubuški, Rog (the seat of Duvno). For the next two centuries after the Ottoman conquest, there is not much information about life in the region of Duvno under Ottoman rule. The reason is that the majority of the population fled from the Ottoman invaders, and today's town was reduced to a small Ottoman kasbah known as Županj-Potok. An anonymous travel writer from the end of the 16th century wrote the following about Županj-Potok: In the middle 16th century, the Ottomans founded a qasaba Županj-Potok. In 1576 Duvno became part of the Kadiluk of Imotski, and it became a kadiluk on its own before 1633. In the second half of the 17th century, Duvno became a part of the Sanjak of Klis, however, it was soon returned to the Herzegovinian Sanjak. On 8 May 1711, Duvno became a captaincy. The seat of captaincy was Županj-Potok. The Captaincy of Duvno was located between the Captaincy of Livno at its north and the Captaincy of Ljubuški at its south; on its west was the Ottoman-Venetian border. Hasan Agha was named the first captain. In 1723, the Ottomans constructed a fort in Županj-Potok and named it Sedidžedid (the new wall), and named the captaincy after it. The population of Duvno suffered heavily during the plagues of 1772, 1773, 1814, and 1815. Hamdija Kreševljaković mentions a borough named Duvno at the end of the 17th century and also states that this borough became a kaza