Claim: Bosnia and Herzegovina is a place.

Croatia -LRB- -LSB- kroʊˈeɪʃə -RSB- ; Hrvatska -LSB- xř̩ʋaːtskaː -RSB- -RRB- , officially the Republic of Croatia -LRB- -LSB- Republika Hrvatska , links = no -RSB- , -RRB- , is a sovereign state between Central Europe , Southeast Europe , and the Mediterranean . Its capital city is Zagreb , which forms one of the country 's primary subdivisions , along with its twenty counties . Croatia covers 56594 km2 and has diverse , mostly continental and Mediterranean climates . Croatia 's Adriatic Sea coast contains more than a thousand islands . The country 's population is 4.28 million , most of whom are Croats , with the most common religious denomination being Roman Catholicism .   The Croats arrived in the area of present-day Croatia during the early part of the 7th century AD . They organised the state into two duchies by the 9th century . Tomislav became the first king by 925 , 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 Petar 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 . During the early 19th century , parts of the country were split into the French Illyrian Provinces , and Austria-Hungary occupied its Bosnia and Herzegovina side -- a dispute settled by the 1878 Treaty of Berlin . In 1918 , after World War I , Croatia was included in the unrecognized State of Slovenes , Croats and Serbs which seceded from Austria-Hungary and merged into the Kingdom of Yugoslavia . A fascist Croatian puppet state backed by Fascist Italy and Nazi Germany existed during World War II . After the war , Croatia became a founding member and a federal constituent of the Socialist Federal Republic of Yugoslavia , a constitutionally socialist state . On 25 June 1991 Croatia declared independence , which came wholly into effect on 8 October of the same year . The Croatian War of Independence was fought successfully during the four years following the declaration .   A unitary state , Croatia is a republic governed under a parliamentary system . The International Monetary Fund classified Croatia as an emerging and developing economy , and the World Bank identified it as a high-income economy . Croatia is a member of the European Union -LRB- EU -RRB- , United Nations -LRB- UN -RRB- , the Council of Europe , NATO , the World Trade Organization -LRB- WTO -RRB- and a founding member of the Union for the Mediterranean . As an active participant in the UN peacekeeping forces , Croatia has contributed troops to the NATO-led mission in Afghanistan and took a non-permanent seat on the UN Security Council for the 2008 -- 2009 term .   The service sector dominates Croatia 's economy , followed by the industrial sector and agriculture . International Tourism is a significant source of revenue during the summer , with Croatia ranked the 18th most popular tourist destination in the world . The state controls a part of the economy , with substantial government expenditure . The European Union is Croatia 's most important trading partner . Since 2000 , the Croatian government constantly invests in infrastructure , especially transport routes and facilities along the Pan-European corridors . Internal sources produce a significant portion of energy in Croatia ; the rest is imported . Croatia provides a universal health care system and free primary and secondary education , while supporting culture through numerous public institutions and corporate investments in media and publishing .