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 – Tarnovo fell in 1393 and Ivan Shishman was killed in 1395. In 1396 Ivan Sratsimir joined the Christian crusade organised by the Hungarian king Sigismund. When the crusader army reached Vidin the Bulgarian ruler opened the gates and surrendered the Ottoman garrison. The Ottoman garrison of Oryahovo tried to resist but the local Bulgarians managed to capture it. However, the Christian army suffered a heavy defeat on 25 September in the battle of Nicopolis and the victorious Ottoman sultan Bayezid I immediately marched to Vidin and seized it by the end of 1396 or the beginning of 1397. Ivan Sratsimir was captured and imprisoned in the Ottoman capital Bursa where he was probably strangled.