A new era dawned for the Habsburg Monarchy after failed Siege of Vienna in 1683, which significantly expanded its territory in southeastern Europe through the wars of the decades to follow. This was also a turning point for the Croatian Kingdom because in the following wars Slavonia and Syrmia were finally liberated. Although they were marked as neoacquista and were not immediately returned to the jurisdiction of the Croatian Ban, estates, and Diet, the unification of Croatian lands under the Habsburg rule opened the way towards the renewal of Slavonian counties. By dividing the civil and military territory and jurisdiction, which was done during the renewal of the counties in 1745, an exclusively military territory was formed along the rivers Sava and Donau which, with the reorganization of the Slavonian Military Frontier in 1747, was divided into three grenzerinfantry regiments: Gradiška, Brodska, and Petrovaradinska. Considering that the grenzer infantry regiments were military-tactical and territorial-administrative units, they had complete authority over the land and its population. The Petrovaradin regiment was established in the Syrmia and encompassed the majority of its area under the military authority, which made it the easternmost of a total of 11 grenzer infantry regiments of the Croatian-Slavonia Military Frontier. Due to its dual nature, the Petrovaradin Regiment was, for the purpose of this dissertation, observed through the perspectives of active military stand and regiment territory as a specification of the military-tactical and territorial-administrative dimension with the aim of researching developmental characteristics, and specialties within the frontier system. Focal points are on the actions of military authorities and the recruitment system, the social structure and characteristics of grenzers, the relationship between military duties and possibilities, war campaigns, and military efficiency. Numerous reform attempts and the aspiration for the professionalization, difficulties in filling prescribed military units, major changes and inner differences, as well as war campaigns across Europe, marked the 18th century for the Petrovaradin regiment. To research the aforementioned phenomena, relevant literature for the 18th century was consulted, as well as primary archival material which bring detailed serial military sources in the form of monthly reports, muster rolls, and revisional, transfer, ascend etc. lists. By emphasizing a single grenzer infantry regiment it is attempted to encompass a wholesome approach on a median military border level and make a contribution to the research of the Slavonian Military Frontier.