(Serbian Cyrillic: Петроварадин, pronounced [petroʋarǎdiːn]) is one of two city municipalities which constitute the city of Novi Sad. As of 2011, the urban area has 27,083 inhabitants, while the municipality has 33,865 people inhabitants. Lying across the river Danube from the main part of Novi Sad, it is built around the Petrovaradin Fortress, historical anchor of the modern city.
Human settlement in the territory of present-day Petrovaradin has been traced as far back as the Stone Age (about 4500 BC). This region was conquered by Celts (in the 4th century BC) and Romans (in the 1st century BC).
The Celts founded the first fortress at this location. It was part of the tribal state of the Scordisci, which had its capital in Singidunum (present-day Belgrade). During the Roman administration, a larger fortress was built (in the 1st century) with the name Cusum and was included into Roman Pannonia. Subsequently, the fortress was included into the Pannonia Inferior and the Pannonia Secunda. In the 5th century, Cusum was devastated by the invasion of the Huns.
The town was then conquered by Ostrogoths, Gepids, and Lombards. By the end of the 5th century, Byzantines had reconstructed the town and called it by the names Cusum and Petrikon or Petrikov. It was part of the Byzantine province of Pannonia. Subsequently, it passed into the hands of Avars, Franks, Pannonian Croats, Pannonian Slavs, Bulgarians, and Byzantines again. During Bulgarian administration, the town was known as Petrik and was part of the domain of duke Sermon, while during subsequent Byzantine administration, it was part of the Theme of Sirmium.
Later, the town became part of the Kingdom of Hungary.
Between 1522 and 1526, Petrovaradin was a base for the early Ŝajkaš regiments, but in 1526, the Ottoman Empire took Petrovaradin after a two-week battle waged against combined forces of Serbs and Hungarians.
In the war of 1683-1699 with the Habsburg Monarchy, the Ottomans abandoned Petrovaradin. In 1690, they returned for just two years. After that, Petrovaradin remained under Habsburg control.
In 1695, a military force of Serbs—600 infantry and 200 cavalry—under Captain Pane Božić were brought to Petrovaradin to serve. One thousand Serbs worked on the Citadel and fortifications.
During Hungarian administration, the town was firstly part of the Bolgyán County and then part of the Syrmia County, while during Ottoman administration, it was firstly part of the vassal duchy of Syrmia ruled by Serb duke Radoslav Čelnik (1527-1530), and then part of the Sanjak of Syrmia.
During the Ottoman administration, Petrovaradin had 200 houses, and three mosques. There was also a Christian quarter with 35 houses populated with Serbs.
Petrovaradin was the site of a notable battle on August 5, 1716 in which the Habsburg Monarchy led by the Prince Eugene of Savoy defeated the forces of the Ottomans led by the Silahdar Damat Ali Pasha. Habsburg forces led by Prince Eugene later defeated the Ottomans at Belgrade before the Ottomans sued for peace at Požarevac.
During the Habsburg administration, Petrovaradin was part of the Habsburg Military Frontier (Slavonian general command – Petrovaradin regiment). In 1848–49, the town was part of Serbian Vojvodina, but in 1849, it was returned under the administration of the Military Frontier. With the abolishment of the Military Frontier in 1881, the town was included into the Syrmia County of Croatia-Slavonia, which was the autonomous kingdom within Austria-Hungary.
In 1918, the town firstly became part of the State of Slovenes, Croats and Serbs, then part of the Kingdom of Serbia and finally part of the Kingdom of Serbs, Croats and Slovenes (later known as Yugoslavia). Between 1918 and 1922, the town was part of the Syrmia County, between 1922 and 1929 part of the Syrmia Oblast, and between 1929 and 1941 part of the Danube Banovina, a province of the Kingdom of Yugoslavia. From 1918 to 1936, Yugoslav Royal Air Force was based in Petrovaradin. During World War II (1941–1944), the town was occupied by the Axis Powers and it was attached to the Independent State of Croatia. Since the end of the war in this part of Yugoslavia in 1944, the town was part of the Autonomous Province of Vojvodina, which from 1945 was part of the new socialist Serbia within socialist Yugoslavia.
Petrovaradin is one of the two city municipalities of the City of Novi Sad and it is located in the northern Serbian province of Vojvodina. Approximately 25-30% of total area of City of Novi Sad (699 km²) is an area of Petrovaradin municipality, which is approximately 100–130 km²; of which approximately 30% is a part of urban area of Novi Sad. Much of land outside of urban area is part of National Park of Fruška Gora.
Petrovaradin Municipality is located in the Syrmia region, on the Danube river and Fruška Gora, a horst mountain with elevation of 78–220 m (municipality up to 451 m). The northern part of Fruška Gora consists of massive landslide zones, but they are not active, except in Ribnjak neighborhood (between Sremska Kamenica and Petrovaradin fortress).