The Military Frontier was a borderland of the Habsburg monarchy and later the Austrian and Austro-Hungarian Empire. It acted as the cordon sanitaire against incursions from the Ottoman Empire.
Migration of the Serbs (Seoba Srba), by Paja Jovanović, portrays Serbian Patriarch Arsenije III Čarnojević, surrounded by soldiers, flocks of sheep and women with babies, leading some 36,000 families from his seat in Peć, to what is now Vojvodina in 1690, after the failure of a Serb revolt.
Various Frontier troops, 1756
Habsburg and Ottoman Empires in 1797, with the Military Frontier (marked in red)
The Hundred Years' Croatian–Ottoman War was a sequence of conflicts, mostly of relatively low intensity, between the Ottoman Empire and the medieval Kingdom of Croatia, and the later Habsburg Kingdom
Otoman troops taking enslaved Christian captives.
Battle of Krbava Field in 1493
The Cetin Charter from 1 January 1527 which confirms the election of Ferdinand Habsburg on position of king of Croatia. The charter shows seals of most distinguished Croatian nobles as well as seal of Croatia.
A town of Karlovac was founded in 2nd half of the 16th century, to serve as a strongpoint in defense against the Ottomans. This picture shows Karlovac star shaped renaissance fort.