 Complete the following phrase:  The relations between the two Bulgarian states worsened in 1381 when Ivan Sratsimir broke the connections with the Bulgarian Patriarchate in Tarnovo and instead placed the Archbishopric of Vidin under the jurisdiction of the Ecumenical Patriarchate of Constantinople. That decision was a demonstration of the independence of Vidin from Tarnovo but did not lead to open conflict between the two. The hostility between Ivan Sratsimir and Ivan Shishman remained on the eve of the Ottoman invasion. Most historians agree that in the 1370s and the early 1380s Vidin was still away from the route of the Ottoman campaigns and was not endangered. During and after the massive Ottoman invasion in north-eastern Bulgaria in 1388, sources suggest that relations between the two brothers were uneasy. As a result of the Ottoman success in the 1388 campaign and the resulting changes of the balance of power, Ivan Sratsimir had to become an Ottoman vassal and to accept an Ottoman garrison in Vidin. Ivan Sratsimir remained inactive while the Ottomans destroyed the remains of the Tarnovo Tsardom 