Based on published and unpublished archival documents, contemporary periodicals and other relevant scientific literature, the author analyzes the sociopolitical situation in the former Vinkovci municipality, from the second half of 1990, when the Serb Democratic Party (SDS) started inciting the Serbian rebellion with the goal of the separation of a part of the Croatian territory from the legitimate constitutional order of the Republic of Croatia and its annexation to Serbia, concluding with armed conflicts in July 1991, when the outright aggression on Croatia began. The situation in the Vinkovci municipality had escalated from protests by the rebel Serbs and illegal referendums on the gerrymandering of the municipalities in the beginning of 1991 to armed guards, barricades and open threats made by rebel Serbs, from the villages which had Serb majority, to Croatian authorities, in the end of April 1991, and then, in the beginning of May 1991, the outright terrorism by the Serbian rebels started, under the aegis of the Yugoslav People's Army (JNA) and supported by the Serbian government. Robberies, kidnappings and murders became an everyday occurrence in the villages of the Vinkovci municipality with the Serb majority, especially in Mirkovci, a rebel stronghold, which had continuously threatened the city of Vinkovci, as well as the surrounding villages. The Croatian armed forces' attempts to neutralize the threat during July 1991, considering the JNA supporting the heavily armed Serbian rebels and the inexperience of the Croatian forces, ended with a failed offensive operation on July 22 1991 (also known as Operation „Silence“), which resulted in heavy casualties for the Croatian Guards and the consolidation of Mirkovci as a „buffer zone“.