Summary/Abstract: In this work is being analyzed the development of the Balkan’s under systems of the international relations, the most complicated node of the national, territorial, inter blocks and the other disputes in the beginning of the twentieth century. The main attention was focused on the Austrian - Serbian conflict and its role in the beginning of the First World War. The crises from July 1914, began at second time to go upon same scenario, but with totally different catastrophic result.
