The Independent State of Croatia (Serbo-Croatian: Nezavisna Država Hrvatska, Независна Држава Хрватска, NDH; German: Unabhängiger Staat Kroatien; Italian: Stato Indipendente di Croazia) was a World War II puppet state of Nazi Germany, established on a part of Axis-occupied Yugoslavia. The NDH was founded on 10 April 1941, after the invasion of Yugoslavia by the Axis powers. All of Bosnia and Herzegovina was annexed to NDH, together with some parts of Serbia.

The state was technically a monarchy and Italian protectorate from the signing of the Rome agreements on 19 May 1941 until the Italian capitulation on 8 September 1943, but the would-be king, appointed by Victor Emmanuel III of Italy, Prince Aimone of Savoy-Aosta, refused to assume the crown in opposition to the Italian annexation of the Croat and Serb-populated Yugoslav region of Dalmatia.

The state was actually controlled by the governing fascist Ustaše movement and its Poglavnik,Ante Pavelić, which in turn were primarily under German influence. For its first two years up to 1943, the state was also a territorial condominium of Germany and Italy. Additionally, central Dalmatia was annexed directly into Italian territory as part of the irredentist agenda of an Italian Mare Nostrum (Our Sea). Italian influence collapsed in 1943, with the ousting of Italian fascist leader Benito Mussolini.

Croatia (ⁱ/kroʊˈeɪʃə/ kroh-AY-shə; Croatian: Hrvatska pronounced [xř̩ʋaːtskaː]), officially the Republic of Croatia (Croatian: Republika Hrvatska  listen (help·info)), is a unitary democratic parliamentary republic in Europe at the crossroads of Central Europe, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers 56,594 square kilometres (21,851 square miles) and has diverse, mostly continental and Mediterranean climates. Croatia's Adriatic Sea coast contains more than a thousand islands. The country's population is 4.29 million, most of whom are Croats, with the most common religious denomination being Roman Catholicism.

In the early 7th century the Croats arrived in area of present-day Croatia. They organised the state into two dukedoms by the 9th century. Tomislav became the first king by 925 AD, elevating Croatia to the status of a kingdom. The Kingdom of Croatia retained its sovereignty for nearly two centuries, reaching its peak during the rule of Kings Peter Krešimir IV and Dmitar Zvonimir. Croatia entered a personal union with Hungary in 1102. In 1527, faced with Ottoman conquest the Croatian Parliament elected Ferdinand I of the House of Habsburg to the Croatian throne. In 1918, after World War I, Croatia was included in the short-lived State of Slovenes, Croats, and Serbs that declared independence from Austria–Hungary and co-founded the Kingdom of Yugoslavia. A Croatian state briefly existed during World War II as a fascist puppet state. After the war, Croatia became a founding member and a federal constituent of the Second Yugoslavia, a socialist state. In June 1991, Croatia declared independence, which came into effect on 8 October of the same year. The Croatian War of Independence was fought successfully during the four years following the declaration.

Independence is a condition of a nation, country, or state in which its residents and population, or some portion thereof, exercise self-government, and usually sovereignty, over its territory. The opposite of independence is dependence.

Attainment of independence should not be confused with revolution, which typically refers to the violent overthrow of a ruling authority. While some revolutions seek and achieve national independence, others aim only to redistribute power — with or without an element of emancipation, such as in democratization — within a state, which as such may remain unaltered. Furthermore, some countries were granted independence without any revolutionary acts. The Russian October Revolution, for example, was not intended to seek national independence; the United States Revolutionary War, however, was.

Autonomy (in slight contrast) refers to a kind of independence which has been granted by an overseeing authority that itself still retains ultimate authority over that territory (see Devolution). A protectorate refers to an autonomous region that depends upon a larger government for its protection as an autonomous region. The dates of established independence (or, less commonly, the commencement of revolution), are typically celebrated as a national holiday known as an independence day.