Herzegovina ( or ; Bosnian, Croatian and Serbian: Hercegovina, Cyrillic: Херцеговина, ) is the southern region of Bosnia and Herzegovina. While there is no official border distinguishing it from the Bosnian region, it is generally accepted that the borders of the region are Croatia to the southwest, Montenegro to the east, the Maglić mountain to the northeast, and Ivan planina to the north. Measurements of the area range from , or around 22% of the total area of the present-day country, to , around 24% of the country. The name Herzegovina means “duke’s land”, referring to the medieval duchy of Stjepan Vukčić Kosača who took title “Herzeg of Saint Sava”. Herceg is derived from the German title Herzog.