The fortress of Požega, an elongated hexagonal fortification located on a hill in the present-day city centre, was probably built during the 11th century, although the first documents that clearly mention Požega county date from 1210, while the city of Požega was documented for the first time in a charter of Andrew II on January 11th, 1227.
The first mention of the city of Požega is found in the Gesta Hungarorum, by an anonymous notary of Béla III (1172–1196) where he mentions the conquest of three forts in Slavonia - as the area between rivers Danube and Sutla was then called: Zagreb, Vlco (Vukovar) and Posega. The fortress of Požega, an elongated hexagonal fortification located on a hill in the present-day city centre, was probably built during the 11th century, although the first documents that clearly mention Požega county date from 1210, while the city of Požega was documented for the first time in a charter of Andrew II on January 11, 1227.
Požega was originally the residential estate of the Croatian-Hungarian queen and was exempt from the authority of the viceroy and the county. Although no such charter survives, the privileges that citizens enjoyed fully corresponded to a free royal city. The fortress doesn't exist anymore, and the irregularly-shaped central city square is Romanic in nature. Only fragments of walls remain to remind that there once stood a fortress. The remaining monuments from that age are the Church of St. Lawrence (first mentioned in 1303), and the Church of the Holy Spirit (built in 1235).
By the late 14th century, the city started to decline economically due to insecurity from Ottoman raids. In the 15th century, city walls were built, replacing a moat that existed before. This proved an insufficient defence as the Turks seized Požega in 1537. During the 150 year long Ottoman rule, Požega was seat of a Sanjak of Požega and given certain prominence. After a considerable economic decline, in 1537, at the time of the Ottoman conquest, Požega reportedly had 110 houses and 15 businesses. However, by 1579, there were 160 craftsmen in Požega as a result of improved security and an increase in population.
The death of Hasan Predojević the Požega Sanjak Bey in the Battle of Sisak in 1593, marked the first Ottoman defeat in Europe, and after years of steady decline, Ottoman rule grew weaker until Požega was finally liberated on 12 March 1688 by citizens led by friar Luka Ibrišimović. This day is now celebrated as the day of the city.
After the liberation, Požega came under Habsburg rule, and in 1745, Požega County was restored and the city thus returned to the authority of Croatian viceroy. Požega underwent a period of vigorous development: In 1699, a grammar school opened - only the fifth in Croatia. In 1727, Jesuits built a theatre, and in 1740, the city's first pharmacy. Finally, the Academia Posegana opened in 1760, placing Požega, along with Zagreb, among the first Croatian centers of highest education.
In 1765, Empress Maria Theresa granted Požega a royal free city charter and supported the construction of the present-day Cathedral of St.Teresa of Ávila. In 1847, Požega was the first city in Croatia to introduce the Croatian language in official use, and the achievements of its notable citizens earned it the nickname of "Slavonian Athens".
Požega County was abolished along with other Croatian counties in 1923, and was restored in 1993, following the independence of Croatia. Furthermore, in the footsteps of its tradition as an educational center as well as a church center, Požega became a diocesan see in 1997, and a graduate-degree college was opened in 1998.