Modern Croatia (from 1990/1991)           

In 1990, the first free elections were held. A people's movement called the Croatian Democratic Union (HDZ) won, led by Franjo Tudman General of Croatian WW2 antifascist movement, the Partisans. HDZ's intentions were to secure more independence for Croatia, contrary to the wishes of part of ethnic Serbs in the republic and official politics in Belgrade. The excessively polarized climate soon escalated into complete estrangement between the two nationalities and even sectarian violence.

In the summer of 1990, Serbs from the mountainous areas where they constitute a relative majority rebelled and formed an unrecognized "Autonomous Region of the Serb Krajina" (later the Republic of Serbian Krajina). Any intervention by the Croatian police was obstructed by the Yugoslav People's Army (JNA), mainly consisting of Serbs. The conflict culminated with the so-called "log revolution", when the Krajina Serbs blocked the roads to the tourist destinations in Dalmatia and started a mass ethnic cleansing of all non-Serb population.

The Croatian government declared independence from Yugoslavia on 25 June 1991, and the JNA launch an open agression on Republic and backing up local Serb militia's. Many Croatian cities, notably Vukovar and Dubrovnik, came under the attack of the Serbian forces. The Croatian Parliament cut all remaining ties with Yugoslavia in October that year.

The civilian population fled the areas of armed conflict en masse: generally speaking, thousands of Croats moved away from the Bosnian and Serbian border, while thousands of Serbs moved towards it. In many places, masses of civilians were forced out by the Yugoslav National Army (JNA), which consisted mostly from conscripts from Serbia and Montenegro, and irregulars from Serbia, in what became known as ethnic cleansing.

The border city of Vukovar underwent a three month siege — the Battle of Vukovar — during which most of the city buildings were destroyed and a majority of the population was forced to flee. The city fell to the Serbian forces in late November 1991. Soon after, shocked with atrocites commited by Serbs, the foreign countries started recognizing Croatia's independence. By the end of January 1992, most of the world recognized the country.

Subsequent UN-sponsored cease-fires followed, and the warring parties mostly entrenched. The Yugoslav People's Army retreated from Croatia into Bosnia and Herzegovina where war was just about to start. During 1992 and 1993, Croatia also handled seven hundred thousands of refugees from Bosnia, mainly Bosnia's Moslems.

Armed conflict in Croatia remained intermittent and mostly on a small scale until 1995. In early August, Croatia started the Operation Storm and quickly reconquered most of the so-called "Republic of Serbian Krajina", leading to a mass exodus of the Serbian population. An estimated 200,000 Serbs fled shortly before, during and after the operation. A few months later, as a result, the war ended upon the negotiation of the Dayton Agreement. A peaceful integration of the remaining Serbian-controlled territories in Eastern Slavonia was completed in 1998 under UN supervision.

President Tudman died in late 1999. In February 2000, Stjepan Mesic was elected president, ending the HDZ's rule. The country underwent many liberal reforms beginning in 2000. An economic recovery as well as healing of many war wounds ensued and the country proceeded to become a member of several important regional and international organizations. The country has started the process of joining the European Union, but a perceived lack of co-operation with the International Criminal Tribunal for the former Yugoslavia concerning the tracking down of the indicted general Ante Gotovina long formed difficulties. After Gotovina's capture on 7 December 2005 the road now seems clear for Croatia to join the EU, although no sooner than 2009.