The origin of the Croatian tribe before the great migration of the Slavs is uncertain. Some people claim that Croats comes from Iran.

According to the most widely theory, in the 7th century, the Croatian tribe moved from the area north of the Carpathians and east of the river Vistula and migrated into the western Dinaric Alps.
White Croats formed the Principality of Dalmatia in the upper Adriatic, while their subgroup Red Croats created the Principalities of Red Croatia. Another wave of Slavic migrants from White Croatia subsequently founded the Principality of Pannonia.

The earliest mention of the Croatian name can be traced on two stone inscriptions in Greek language and script, dating from around the year 200, found by the Black Sea. Both stone tablets are held in the Archeological museum in St Petersburg, Russia.

Instantly with coming (7th century), Croats took over native Illyrian-Roman provinces of Dalmatia and Pannonia, which then were ruled by various Croatian rulers.
Eventually Croatia became an independent kingdom in 925, when, by a decree of the Holy Catholic Church in Rome, King Tomislav was crowned as king of Croatia.

Croatia retained its independence until 1102 when, after decades of inner seizing’s, the country entered a dynastic union with Kingdom of Hungary. Croatian statehood was preserved through a number of institutions, notably the council which served as an assembly of Croatian nobles. The Croatian nobles retained their lands and titles.

In 1242 a Tatar invasion devastated Croatia.

By the mid-1400s, as the Turks threatened to take over the Balkans, northern Croatia turned to the Habsburgs of Austria for protection, remaining under their influence until 1918.

The odd crescent shape of the Croatian lands remained as a mark, more or less, of the frontier to the Ottoman advance into Europe.

Meanwhile, the Dalmatian coast was taken by Venice in the early 15th century and held until the end of the 17th century, when it was taken by Napoleon and made part of the Illyrian provinces.
Dubrovnik was a city-state, but later, unlike other Dalmatian city-states, became independent as Republic of Dubrovnik; it was often under the supremacy of neighboring powers.

When the Austro-Hungarian Empire was defeated in World War I, Croatia became part of the Kingdom of Serbs, Croats and Slovenes, which eventually became Kingdom of Yugoslavia in 1929. Croatian nationalists were angered that Belgrade was made capital of the union.

In 1941 Germany and its Axis allies invaded Yugoslavia and set up the extreme right-wing organization (the Ustashe), backed and sponsored by Italian fascists, to found the "Independent State of Croatia".
Not all Croats agreed with this policy, and many joined with the communist partisans to overthrow the Ustashe.
By the time the war ended, about a million people had died in Croatia and Bosnia-Herzegovina.

When the German powers were defeated in Croatia by the anti-fascists, the State Anti-Fascist Council declared the People's Republic of Croatia, which became one of the six socialist republics within federal Yugoslavia.

After World War II, Croatia has republic status within the Yugoslav Federation, conducted by the communist Marshal Tito.
As Croatia outstripped the southern republics economically, it demanded greater autonomy, bringing a series of purges down on the heads of its residents during the 1970s. When Tito died in 1980, an artificial political system was instituted which resulted in the presidency rotating annually between the republics, and Croatia's economy ground to a halt.

As communist governments fell throughout Eastern Europe, Croats began agitating for autonomy and an end to communism.

Croatia declared its independence from Yugoslavia on June 25, 1991, which triggered the Croatian War of Independence. The Serb population living in Croatia revolted, supported by the Yugoslav army and paramilitary extremist groups from Serbia. The ensuing months saw combat between newly established Croatian Army and associated Yugoslav and Serb armed forces. Following this stage of the war, Croatia was recognized on 15 January 1992 as an independent state by the European Union. Finally the independence of Croatia was internationally recognized.
During the war, the Croatian Serbs proclaimed their own state in areas where they made up relative or absolute ethnic majority, the "Republic of Serbian Krajina", a short lived territory without any international recognition. The war left hundreds of thousands refugees on the Croatian side, and thousands were killed either in battle or by ethnic cleansing. The war ended in 1995, after the Croatian Army successfully launched two major military operations to recapture the occupied area.

At the time of first modern Croatia's the constitution has been changed to shift power away from the president to the parliament. Croatia has joined the World Trade Organization and opened up the economy, making it grow while inflation was kept under control. It joined NATO's Partnership for Peace program and became an official candidate for membership in that alliance. By 2003 it had made sufficient progress to apply for European Union membership; the country is expected to become an EU member state 2010.