During the course of the eighteenth century the Habsburg Monarchy, one of the leading European powers, participated in numerous wars with the aim of expanding its borders, but also of protecting its dispersed lands, as well as maintaining equilibrium among the European states. At the end of the seventeenth century the army of the Ottoman Empire, the main threat to the existence of the Habsburg Monarchy, experienced a crushing defeat in front of the walls of Vienna, after which the Habsburg military forces took the offensive and initiated an expansion of the Habsburg borders towards the southeast. Among the new territorial acquisitions of this expansion were the regions of Lika and Krbava, territories which had been lost to the Ottomans in the first half of the sixteenth century. Although initially a civil administration was supposed to be established in these regions, due to the defiant nature of the inhabitants who initiated several uprisings demanding Grenzer status, in 1712 they were incorporated in the Croatian-Slavonian Military Frontier. In the middle of the eighteenth century, a reorganization of the Military Frontier was carried out, entailing the establishment of Grenzer regiments, which were designed to function simultaneously as military and territorial units. This reform was associated with the modification of the role of the Grenzer, who were initially charged with defending the Habsburg borders from Ottoman incursions, but during the course of the eighteenth century, they were awarded the additional task of participating in the various wars being waged by their Habsburg rulers on distant European battlefields. Precisely from the middle of the eighteenth century, the Grenzer started to march more intensively to the western battlefields. This dissertation is focused on exploring the military involvement and living conditions of the Grenzer inhabiting the region of the Lika Regiment, one of the least explored areas of the Croatian-Slavonian Military Frontier. The geographical features of the land, as well as its position in regard to its distance from the center of the Generalcy, and its adjacency to both the lands of the Ottoman Empire and the Venetian Republic had a great impact on the development of this region and the living conditions of its inhabitants. The research is based on the inquiry of relevant literature which deals with Grenzer and military history of the eighteenth century, as well as various original sources, such as war reports, military lists, newspaper articles, and manuscripts. The military activity of the Grenzer of Lika is placed within a wider aspect of warfare and military life in the eighteenth century by comparing the conditions of the Grenzer of Lika with other contemporary soldiers, as well as other Grenzer groups. The main aim is to distinguish the features of this specific Grenzer group. Besides that, their example also provides an opportunity for outlining some of the general features of military life and the military profession in the mentioned century.