Fall to Ottoman Power (1371–1396)

Following the death of Tsar Ivan Alexander in 1371, the once unified Bulgarian state fragmented into three separate political entities: the Tarnovo Tsardom under Ivan Shishman, the Vidin Tsardom under his elder brother Ivan Sratsimir, and the Karvuna appanage or Dobruja under Ivanko. This division reflected the ongoing feudalization and internal family disputes, weakening the Bulgarian state at a critical time when the Ottoman Empire was expanding aggressively into the Balkans.

Ivan Shishman inherited the Tarnovo throne and the traditional Bulgarian political ideology, styling himself as "Tsar and autocrat of all Bulgarians and Greeks," a title reflecting his claim to the Bulgarian legacy and authority. However, his reign was marked by the end of traditional Bulgarian foreign policy centered on Byzantium, as the Ottomans replaced the Byzantines as the primary external power. Lacking significant political experience, Ivan Shishman sought various strategies to preserve his realm, including diplomatic maneuvering, vassalage, marriage alliances, and attempts to organize coalitions with Serbia and Hungary. Despite these efforts, his position was precarious, and the Ottoman threat loomed large.

The Ottomans steadily advanced into Bulgarian territories, capturing key fortresses and cities. After the catastrophic Battle of Chernomen in 1371, where Christian forces were defeated, the Ottomans penetrated deeper into the Balkans. Sofia fell in 1382 after a prolonged siege, and although Ivan Shishman could not assist, this loss signaled the growing Ottoman dominance. In 1388, a major Ottoman campaign led by Grand Vizier Ali Pasha crossed the Balkan Mountains, seizing important towns such as Shumen and Provadia, and besieging Ivan Shishman in Nikopol. The Bulgarian tsar was forced to seek peace, ceding Silistra as part of the agreement. However, Ivan Shishman later reneged on handing over Silistra, leading to renewed Ottoman pressure.

The Ottomans eventually captured Tarnovo in 1393, but Ivan Shishman had relocated to Nikopol before the city's fall. He continued to rule as a vassal or local governor under Ottoman suzerainty, but his days were numbered. After the Battle of Rovine in 1395, Sultan Bayezid I ordered Ivan Shishman's execution, ending his life and reign. His death marked the definitive collapse of the Tarnovo Tsardom. Meanwhile, Ivan Sratsimir in Vidin and Ivanko in Dobruja also faced Ottoman encroachment. Vidin fell shortly after, with Ivan Sratsimir captured and taken to Bursa, dying in captivity. His heir fled to Hungary and later Serbia.

The Ottoman conquest transformed Bulgarian lands into Ottoman provinces, with Silistra becoming a sanjak center. Some Bulgarian rulers, including Ivan Shishman and Ivanko, were retained as Ottoman vassals for a time, but their autonomy was severely limited. The loss of the Bulgarian capital and the deaths or captivity of its rulers symbolized the end of medieval Bulgarian statehood. The period was marked by fear, resignation, and a collapse of traditional leadership, as described in contemporary sources that lament the suffering and despair of the Bulgarian people.

Despite the tragic outcome, Ivan Shishman is remembered in folklore and historical memory as the last medieval Bulgarian tsar who struggled against overwhelming odds. His attempts at diplomacy, coalition-building, and resistance, though ultimately unsuccessful, reflect the complex and desperate efforts of a declining state confronting a rising empire. The fall of the Second Bulgarian Empire thus stands as a pivotal moment in Balkan history, marking the transition from medieval Christian kingdoms to Ottoman rule.