it separate from the Duchy of Carniola. The county was soon leased out to the House of Celje, which acquired full rights of the lords of the land in 1443. It remained part of the Celje domains until their extinction in 1457, whereafter it reverted to the Habsburgs, who gradually incorporated it into Carniola. Early modern period With the Ottoman conquest of Serbian territories, groups of Serbs fled to the north or west; of the western migrational groups, some settled in White Carniola and Žumberak. Vlachs and Uskoks to White Carniola and Žumberak coming from Croatia and Bosnia. The Habsburg commanders brought from Bosnia, later and from parts of Croatia and Dalmatia hundreds or thousands of families and settled them in area which covers White Carniola, across the Žumberak Mountains all the way to Vinica. In September 1597, with the fall of Slatina, some 1,700 Uskoks with their wives and children settled in Carniola, bringing some 4,000 sheep with them. The following year, with the conquest of Cernik, some 500 Uskok families settled in Carniola. At the end of the 17th century, with the stagnation of Ottoman power due to European pressure during internal crisis, and Austrian advance far into Macedonia, Serbs armed themselves and joined the fight against the Ottomans; the Austrian retreat prompted another massive exodus of Serbs from the Ottoman territories 1690 (see Great Serb Migrations). In his 1689 work The Glory of the Duchy of Carniola, the historian Johann Weikhard von Valvasor described the language, clothing, and customs of the people of White Carniola region as Croatian. The self-identification of students on the university registers in Graz and Vienna between 1643 and 1712 shows that as many as 88% of students from White Carniola identified as Croats, and only 12% as Carniolans. The provincial designation 'Croats' (Crovathen/Crobathen) was used for White Carniola in 1709, and the name 'Croats' for the inhabitants of White Carniola is found in 1725 in a report by a doctor named Zalokar from Novo Mesto. The dialect of the parish of Vinica in far southern White Carniola was marked as Croatian in 1795. Buildings Castles Several castles were built in the border region, especially during the Ottoman Wars from the 15th century onwards, as in Črnomelj, Gradac and Vinica. The remains of the large fortress in Pobrežje were destroyed in World War II. Culture Based on surnames found in White Carniola, it