The area known as Croatia today was inhabited throughout the prehistoric period. Neanderthal fossils dating
to the middle Palaeolithic period were unearthed in northern Croatia, best presented at the Krapina site.
Remnants of Neolithic and Chalcolithic cultures were found in all regions. The largest proportion of sites is in the
valleys of northern Croatia. The most significant are Baden (3520–2690 BC), Starčevo (3520–2690 BC), and
Vučedol cultures (3000 and 2200 BC).
Iron Age hosted the early Illyrian Hallstatt culture (1200 – 450 BC) and the Celtic La Tène culture (450 — 1 BC).
Before the Roman expansion, the eastern Adriatic coast formed the northern part of the Illyrian kingdom from the
4th century BC to the Illyro-Roman Wars in the 220s BC. In 168 BC, the Roman Republic established its
protectorate south of the Neretva river. The area north of the Neretva was slowly incorporated into Roman possession
until the province of Illyricum was formally established 32–27 BC.
Between 6 and 9 AD, tribes including the Dalmatae, who gave name to these lands, rose up against the Romans in
the Great Illyrian revolt, but the uprising was crushed, and in 10 AD Illyricum was split into two provinces —
Pannonia and Dalmatia. The province of Dalmatia spread inland to cover all of the Dinaric Alps and most
of the eastern Adriatic coast. Dalmatia was the birthplace of the Roman Emperor Diocletian, who, when he retired
as Emperor in 305 AD, built a large palace near Salona, from which the city of Split later developed.
After the Western Roman Empire collapsed in 476, with the beginning of the Migration Period, Julius Nepos
briefly ruled his diminished domain from Diocletian's Palace after his 476 flight from Italy. The region was then
ruled by the Ostrogoths until 535 when Justinian I added the territory to the Byzantine Empire.
The Roman period ended with the Avar and Croat invasions in the 6th and 7th centuries and the destruction
of almost all Roman towns.
From the middle of the seventh century until the unification in 925, there were two duchies on the territory of today's
Croatia, Duchy of Croatia and Principality of Lower Pannonia.
Tomislav was the first king of Croatia, noted as such in a letter of Pope John X in 925. Tomislav defeated
Hungarian and Bulgarian invasions. The medieval Croatian kingdom reached its peak in the 11th century during the reigns
of Petar Krešimir IV (1058–1074) and Dmitar Zvonimir (1075–1089).
When Stjepan II died in 1091, ending the Trpimirović dynasty, Dmitar Zvonimir's brother-in-law Ladislaus I
of Hungary claimed the Croatian crown. This led to a war and personal union with Hungary in 1102 under Coloman.
For the next four centuries, the Kingdom of Croatia was ruled by the Sabor (parliament) and a Ban (viceroy)
appointed by the king. This period saw the rise of influential nobility such as the Frankopan and Šubić
families to prominence, and ultimately numerous Bans from the two families.
An increasing threat of Ottoman conquest and a struggle against the Republic of Venice for control of coastal
areas ensued. The Venetians controlled most of Dalmatia by 1428, except the city-state of Dubrovnik, which became
independent. Ottoman conquests led to the 1493 Battle of Krbava field and the 1526 Battle of Mohács, both
ending in decisive Ottoman victories.
King Louis II died at Mohács, and in 1527, the Croatian Parliament met in Cetin and chose Ferdinand I of the
House of Habsburg as the new ruler of Croatia, under the condition that he protects Croatia against the Ottoman
Empire while respecting its political rights.
Following the decisive Ottoman victories, Croatia was split into civilian and military territories in 1538. The military
territories became known as the Croatian Military Frontier and were under direct Habsburg control.
Until the 18th century, the kingdom included only a small north-western part of present-day Croatia around Zagreb, and
a small strip of coastland around Rijeka, that were not part of the Ottoman Empire or part of the Croatian Military Frontier.
The territory of the Slavonian kingdom was recovered from the Ottoman Empire, and was subsequently part of the Military
Frontier for a short period. In 1744, these territories were organized as the Kingdom of Slavonia and included within
the Kingdom of Croatia as an autonomous part. In 1868, they were merged into the newly formed Kingdom of Croatia-Slavonia.
After Austria-Hungary occupied Bosnia and Herzegovina following the 1878 Treaty of Berlin, the Military Frontier
was abolished. The Croatian and Slavonian sectors of the Frontier returned to Croatia in 1881, under provisions
of the Croatian–Hungarian Settlement. Renewed efforts to reform Austria-Hungary, entailing federalisation with Croatia
as a federal unit, were stopped by World War I.
On 29 October 1918 the Croatian Parliament (Sabor) declared independence and decided to join the newly formed State
of Slovenes, Croats, and Serbs, which in turn entered into union with the Kingdom of Serbia on 4 December 1918 to form
the Kingdom of Serbs, Croats, and Slovenes, in 1929 it was formally renamed the "Kingdom of Yugoslavia".
In April 1941, Yugoslavia was occupied by Nazi Germany and Fascist Italy. Following the invasion, a German-Italian installed
puppet state named the Independent State of Croatia was established. Most of Croatia, Bosnia and Herzegovina, and
the region of Syrmia were incorporated into this state. Parts of Dalmatia were annexed by Italy, Hungary annexed the
northern Croatian regions of Baranja and Međimurje.
The anti-fascist communist-led Partisan movement, based on a pan-Yugoslav ideology, emerged in early 1941 under
the command of Croatian-born Josip Broz Tito, and spread quickly into many parts of Yugoslavia. By 1943, the Partisan
resistance movement had gained the upper hand and in 1945, with help from the Soviet Red Army, expelled the Axis
forces and local supporters.
After World War II, Croatia became a single-party socialist federal unit of the Socialist Federal Republic of
Yugoslavia, ruled by the Communists, but having a degree of autonomy within the federation.
In 1980, after Tito's death, economic, political, and religious difficulties started to mount and the federal government
began to crumble. In 1986, the emergence of Slobodan Milošević in Serbia provoked a very negative reaction in
Croatia and Slovenia; politicians from both republics feared that his motives would threaten their republics' autonomy.
As tensions rose, Croatia declared independence on 25 June 1991. In the meantime, tensions escalated into Croatian War
of Independence when the Serbian-controlled Yugoslav People's Army and various Serb paramilitary groups attacked Croatia.
Armed conflict in Croatia remained intermittent and mostly small-scale until 1995. In early August, Croatia embarked on
Operation Storm, an attack that quickly reconquered most of the territories.
Following the country's independence from Yugoslavia, Franjo Tuđman became the first president of Croatia and
served as president from 1990 until his death in 1999.
In the early 2000 parliamentary elections, the nationalist Croatian Democratic Union government was replaced by a
center-left coalition under the Social Democratic Party of Croatia, with Ivica Račan as prime minister. At the same
time, presidential elections were held which were won by a moderate, Stjepan Mesić. The new Račan government
amended the constitution, changing the political system from a presidential system to a parliamentary system,
transferring most executive presidential powers from the president to the institutions of the parliament and the
prime minister.
On 30 June 2011, Croatia successfully completed EU accession negotiations. The country signed the Accession Treaty on
9 December 2011 and held a referendum on 22 January 2012, where Croatian citizens voted in favor of an EU membership.
Croatia joined the European Union on 1 July 2013.
On 1 January 2023 Croatia adopted the euro as its official currency, replacing the kuna, and became the 20th
Eurozone member. On the same day, Croatia became the 27th member of the border-free Schengen Area, thus marking
its full EU integration.