 Complete the following phrase:  After the death of Ivan Alexander in 1371 Ivan Sratsimir broke off ties with Tarnovo and even placed the archbishop of Vidin under the jurisdiction of the Patriarchate of Constantinople to demonstrate his independence. Due to its geographical position, Vidin was initially safe from attacks by the Ottoman Turks who were ravaging the Balkans to the south and Ivan Sratsimir made no attempts to assist Ivan Shishman in his struggle against the Ottomans. Only after the 