The Napoleonic Wars engulfed Croatia. In these wars, Venice disappeared in 1797, and its possessions on the eastern coast of the Adriatic Sea were taken by Austria. In this manner Croatia and Slavonia were united with Dalmatia in the same state. In 1805, France took these regions away from Austria, and in 1809 they acquired Croatia south of the Sava after defeating Austria, and created the so-called Illyrian Provinces which existed until 1813. Napoleon's army entered Dubrovnik in 1806 to protect it from plunder by Russians and Montenegrans, and in the same year France proclaimed the dissolution of the Dubrovnik Republic. After the defeat of Napoleon, all of these regions, together with Boka Kotorska, were ceded to Austria, so that almost all of the Croatian lands were in the same state - the Habsburg Monarchy.
Under the influence of the French Revolution, and because of resistance to Germanization and Magyarization and the internal development of rich cultural and state traditions, a national renewal took place in Croatia from 1830 to 1848. In the hope of uniting all of the South Slavs, the Croats did not only use their national, Croatian, name. They also used the supranational, Illyrian, name, so that this renewal is usually called the Illyrian Movement. Due in large part to Ljudevit Gaj, Janko Draskovic and the previous work of Bishop Maksimilijan Vrhovac, the Croats standardized their literary language and alphabet, and established newspapers and national institutions. They ceased to use Latin, and did not accept the imposition of German or Hungarian, and from 1847 began to use their Croatian language. In this way they gathered all Croatian lands around Zagreb, influenced the Croatian renewal in Dalmatia, Istria, Bosnia-Herzegovina and Backa. The Slovenians partially accepted the ideas of the Illyrian Movement, but the Serbs rejected the neutral Illyrian name and would only accept the Serbian name and the idea of creating an independent Serbia, and then a Greater Serbia, at the expense of Bosnia, Herzegovina, Croatia, Bulgaria, Macedonia and Albania.
The Revolution of 1848 also engulfed Croatia, which Ban Josip Jelacic united under his government, and the Croatian parliament passed a national program, abolished serfdom and established the idea of the unification of all Croatian lands as a foundation. In 1848, the Croats resisted the Hungarians with arms, as the Hungarians did not recognize Croatian autonomy, but both became the victims of Austrian absolutism from 1850 to 1860. In their parliament in 1861, the Croats put forth their demands for the unification of all Croatian lands, created closer ties with Hungary, rejected ties with Austria and drafted their program for an independent Croatia for the first time (Ante Starcevic, Eugen Kvaternik). After being defeated by the Prussians, Austria reorganized itself as Austria-Hungary (1867), and the Croatian lands were divided between these two, while Civil Croatia obtained internal autonomy through the Croatian- Hungarian Compromise, which no other part of the Austro-Hungarian Empire had.
After the Berlin Congress in 1878, Austria- Hungary obtained Bosnia-Herzegovina, so that the Croats living there found themselves living in the same state with the rest of the Croats people. When the Military Frontier was dissolved in 1881, its parts were united by historical right to their mother country, Croatia, whose administrative, political and cultural center was Zagreb. However, Dalmatia, Boka Kotorska and Istria were still in the Austrian part of the monarchy, and Rijeka, as a port, and Medjimurje were administered by Hungary, despite the fact that the Croatian parliament sought the unification of all Croatian lands. This situation was maintained until 1918, when the Austro-Hungarian Empire fell. Unification with the Military Frontier enlarged the number of Serbs in Croatia. These were the descendents of the aforementioned Vlach stock-herders who were settled in Croatian lands during the Turkish conquests. In the course of the nineteenth century they accepted Serbian national affiliation because they shared the same Orthodox faith with the Serbs. They demanded a separate language, the use of the Cyrillic alphabet and cultural and political autonomy. One part of these people, prompted from Serbia, worked on the separation of the former territory of the Military Frontier and unification with the Kingdom of Serbia. This was the so-called Greater Serbia program, in which parts of Croatia, Bosnia- Herzegovina, the Principality of Montenegro, Macedonia, etc., were supposed to be annexed by Serbia.
These political aspirations for conquest by the Serbs and Serbia, called the Serbian question, were the cause of instability in the region, and this has remained so until the present day. After the Croatian national renewal, political parties were established in Croatia. The strongest of these was the National Party (Narodna stranka), led by the well-known bishop, Josip Juraj Strossmayer. This party practiced pragmatic policies, working on the enlightenment of Croatia and the consolidation of all South Slavs around Zagreb, on the basis of the so-called Yugoslav idea or Yugoslavism. In 1861, the Party of the Right (Stranka prava) was established. This party advocated an independent Croatia and opposed cooperation with Austria, Hungary and Serbia. The First World War broke out in this political struggle in the triangle between Vienna, Budapest and Belgrade and in the attempts to unite all of the Croatian lands. Austria-Hungary lost this war and was broken up into several states. The decision on the cessation of all state and legal ties with the old Habsburg Monarchy could only be passed by the Croatian parliament as the representative of the historical sovereignty of Croatia. It did this on October 29, 1918. A short-lived State of Slovenes, Croats and Serbs was created from the South Slav lands of the Austro-Hungarian Empire in October of 1918.
The leadership of this state was composed by the National Council of the Slovenes, Croats and Serbs, with its seat in Zagreb. This state was threatened in the west by Italy, which as one of the victors of the war sought the Croatian Adriatic coast. On the other side, Serbia, also on the side of the victors, made advances through its army, taking Montenegro and Vojvodina and proposing unification with the State of Slovenes, Croats and Serbs in a centralized monarchy under the Serbian Karadjordjevic dynasty. The leadership of the SHS state, led by Serb Svetozar Pribicevic and Slovene Anton Korosec, agreed to unification, so that on December 1 , 1918, the Kingdom of Serbs, Croats and Slovenes (SHS) with its center in Belgrade, was proclaimed in Belgrade. In his reply to the Address of the National Council Delegation, Regent Alexander himself explicitly proclaimed "the unification of Serbia with 385 the lands of the independent State of the Slovenes, Croats and Serbs into a united Kingdom of Serbs, Croats and Slovenes".