Military Frontier in the context of "Novorossiya Governorate"

The Treaty of Karlowitz, concluding the Great Turkish War of 1683–1699, in which the Ottoman Empire was defeated by the Holy League at the Battle of Zenta, was signed in Karlowitz (present-day Sremski Karlovci, Serbia), in the Military Frontier of the Habsburg Monarchy, on 26 January 1699. Also known as "The Austrian treaty that saved Europe", it marks the end of Ottoman control in much of Central Europe, with their first major territorial losses in Europe, beginning the reversal of almost three centuries of expansion (1299–1683). The treaty established the Habsburg monarchy as the dominant power of the region.

The Kingdom of Slavonia (Croatian: Kraljevina Slavonija, Latin: Regnum Sclavoniae, Hungarian: Szlavón Királyság, German: Königreich Slawonien, Serbian Cyrillic: Краљевина Славонија) was a kingdom of the Habsburg monarchy and the Austrian Empire that existed from 1699 to 1868. The kingdom included northern parts of present-day regions of Slavonia (today in Croatia) and Syrmia (today in Serbia and Croatia). The southern parts of these regions were part of the Slavonian Military Frontier, which was a component of the Military Frontier separating the Habsburg monarchy from the Ottoman Empire.

The Serbs of Croatia or Croatian Serbs, are a recognized ethnic minority in Croatia. According to data from the 2021 census, the population of ethnic Serbs in Croatia is 123,892, constituting 3.2% of the total population.

In some regions of modern-day Croatia, such as southern Dalmatia, ethnic Serbs have been present from the Early Middle Ages. Serbs from modern-day Serbia and Bosnia and Herzegovina started migrating to Croatia during the Habsburg monarchy's long series of wars against the Ottoman Empire. Several migration waves of Serbs occurred after 1538, when Habsburg Monarchy granted them the right to settle on the territory of the Military Frontier, populating the Dalmatian Hinterland, Lika, Kordun, Banija, and Slavonia. In exchange for land and exemption from taxation, they had to conduct military service and participate in the protection of the border. Following the 1848 revolution and the abolition of the Military Frontier in the 1870s-1880s, rising Croatian national sentiment and the growth of Yugoslav-oriented ideas among some Serb intellectuals led to increasing political tension, culminating in the formation of the Serb Independent Party and growing rivalry with Croatian nationalist movements.

Vuk II Krsto Frankopan Tržački (English: Wolf II Christopher Frankopan of Tržac) was a Croatian nobleman and soldier of the Frankopan family, father of noted poet and politician Fran Krsto Frankopan. He was born about 1588.

He was the son of Gašpar I Frankopan Tržački, captain of Ogulin, and his wife Katarina née Lenković, daughter of Ivan Lenković, Uskoks leader. Educated in Ljubljana and in Italy, he started his military career as officer on the Croatian Military Frontier, later becoming a commander of Tržan Castle in Modruš (1612), captain of Ogulin (1618) and lieutenant colonel of Senj (1620).

The Battle of Sisak was fought on 22 June 1593 between Ottoman Bosnian forces and a combined Christian army from the Habsburg lands, mainly the Kingdom of Croatia and Inner Austria. The battle took place at Sisak, central Croatia, at the confluence of the Sava and Kupa rivers, on the borderland between Christian Europe and the Ottoman Empire.

Between 1591 and 1593 the Ottoman military governor of Bosnia, Beglerbeg Telli Hasan Pasha, attempted twice to capture the fortress of Sisak, one of the garrisoned castles that the Habsburgs maintained in Croatia as part of the Military Frontier. In 1592, after the key imperial fortress of Bihać fell to the Turks, only Sisak stood in the way before Croatia's main city Zagreb. Pope Clement VIII called for a Christian league against the Ottomans, and the Sabor recruited in anticipation a force of about 5,000 professional soldiers.

Serb Independent Party (Serbian: Srpska samostalna stranka, SSS, German: Serbische selbständige Partei), also known as Serb Autonomous Party or simply Serb Autonomists, was an ethnic Serb political party in the Kingdom of Croatia-Slavonia, under the Austro-Hungarian Empire. It was established in August 1881, in Ruma, by Pavle Jovanović and other affluent Serbs. In 1903 Svetozar Pribićević (1875–1936) became the party leader. They published Srbobran, which was the party organ. The party advocated for the unification of Lika, Kordun, Banija, Dalmatia, Slavonia and Bosnia and Herzegovina with Serbia to form a Greater Serbia. It was later one of the key members of the Croat-Serb coalition (formed in 1905).

It was formed by the Serbs of Croatia in response to the merging of the Military Frontier, inhabited by the Serbs, back into the Kingdom of Croatia.

The Croatian Military Frontier (Croatian: Hrvatska vojna krajina or Hrvatska vojna granica) was a district of the Military Frontier, a territory in the Habsburg monarchy, first during the period of the Austrian Empire and then during Austria-Hungary.

The Republic of Serbian Krajina or Serb Republic of Krajina (Serbian: Република Српска Крајина / Republika Srpska Krajina, pronounced [rɛpǔblika sr̩̂pskaː krâjina]; abbr. РСК / RSK), known as the Serbian Krajina (Српска Крајина / Srpska Krajina) or simply Krajina (Крајина), was an unrecognized geopolitical entity and a self-proclaimed Serb quasi-state, a territory within the newly independent Republic of Croatia (formerly part of Socialist Yugoslavia), which it defied, and which was active during the Croatian War of Independence (1991–95). It was not recognized internationally. The name Krajina ("Frontier") was adopted from the historical Military Frontier of the Habsburg monarchy (Austria-Hungary), which had a substantial Serb population and existed up to the late 19th century. The RSK government waged a war for ethnic Serb independence from Croatia and unification with the Federal Republic of Yugoslavia and Republika Srpska (in Bosnia and Herzegovina).

The government of Krajina had de facto control over central parts of the territory while control of the outskirts changed with the successes and failures of its military activities. The territory was legally protected by the United Nations Protection Force (UNPROFOR). Its main portion was overrun by Croatian forces in 1995 and the Republic of Serbian Krajina was ultimately disbanded as a result. A rump remained in eastern Slavonia under UNTAES administration until its peaceful reintegration into Croatia in 1998 under the Erdut Agreement.