Croatia, officially the Republic of Croatia, is a country in Central and Southeast Europe, on the coast of the Adriatic Sea. It borders Slovenia to the northwest, Hungary to the northeast, Serbia to the east, Bosnia and Herzegovina and Montenegro to the southeast, and shares a maritime border with Italy to the west. Its capital and largest city, Zagreb, forms one of the country's primary subdivisions, with twenty counties. Other major urban centers include Split, Rijeka and Osijek. The country spans 56,594 square kilometres (21,851 square miles), and has a population of nearly 3.9 million.
The Croats arrived in modern-day Croatia, then part of Roman Illyria, in the late 6th century. In the 7th century, they organized the territory into two duchies.