The Treaty of Berlin was signed on 13 July 1878. In the aftermath of the Russian victory against the Ottoman Empire in the Russo-Turkish War of 1877–1878, the major powers restructured the map of the Balkan region. They reversed some of the extreme gains claimed by Russia in the preliminary Treaty of San Stefano, but the Ottomans lost their major holdings in Europe. It was one of three major peace agreements in the period after the 1815 Congress of Vienna. It was the final act of the Congress of Berlin and included the United Kingdom, Austria-Hungary, France, Germany, Italy, Russia and the Ottoman Empire. Chancellor of Germany Otto von Bismarck was the chairman and dominant personality.