There are very few cities in the world whose exact date of establishment is known by historians and the city of Karlovac is one of them. Namely, the city was established on 13 July 1579. It was named after its founder, Archduke Charles of Habsburg. This early period of the city’s history was also marked by the beginning of works on the erection of the military frontier fortification, which served as a defence against Ottoman attacks. The City Day of Karlovac is celebrated every year on July 13, on which occasion the local city authorities organise a birthday ball at the Ban Josip Jelačić Square, the City Council holds a ceremonial sitting and people with notable achievements are presented with awards. The patron saint of the city is Saint Joseph, whose feast is celebrated on March 19. The central celebration of the Feast of Saint Joseph is held in the Saint Joseph Church located in the city area of Karlovac called Dubovac, which holds the status of national shrine of Saint Joseph.
In 1778, Karlovac got its first city government, and in 1781 the city was granted the status of “a royal free city” by virtue of a Decree issued by Emperor Joseph II. The city was built in accordance with the latest construction standards of its time: it was built in the Renaissance style and has a geometrically regular shape of a six-pointed star. Pursuant to the urban plan from the late 19th and early 20th century, it was decided that municipal palaces would be constructed and that parks and woodlands would be landscaped along the edges of the fortification. It is thus that Karlovac became and still remains a city that is, on one hand, a typical Renaissance-style town and on the other a hexagonal fortification with bastions and a grid plan of streets running at right angles. It is this interesting combination that makes Karlovac a unique European city.