The Sunja bridgehead, centered in the town of Sunja, is located on the right bank of the Sava River. Sunja has a very significant historical and geographical role, which it achieved as a railway and transport hub. This work is based on the study of the socio-political situation before and during the Homeland War, as an introduction to the main topic. Due to its geographical position, Sunja has a significant role in the defense of Sisak and the right bank of the Sava River, i.e., the left flank of the defense of Sisak. By analyzing the broader picture of the Sunja area, surrounded by the Banovina-Kordun and West Slavonia battlefields, an insight will be provided into the operational-strategic importance of the Sunja bridgehead. The main focus of the work will be on the operational-strategic significance of the Sunja bridgehead in the Homeland War. The work deeply analyzes the concept of the broader operational-strategic importance of the Banovina battlefield, the military-political goals of the opponents (the Yugoslav People's Army and the rebel Serbs), and the goals of the Croatian authorities, as well as the police and military forces. The emphasis of the work is placed on the defense of Sunja, describing the initial phase of the rebellion and aggression on Sunja and the arrival of UN forces. Finally, the work highlights the importance of the bridgehead as a starting point in Operation Storm. The thesis provides a comprehensive overview of the pre-war situation in Sunja and the importance of the Sunja bridgehead during the Homeland War.