The Serbian king, Stefan Vladislav, had married Beloslava, daughter of Tsar Ivan Asen II of Bulgaria, in 1234 in an effort to form an anti-Hungarian alliance.
[4] A separate group of Cumans entered Bulgaria about the same time, crossing the Black Sea after the Mongol conquest of Cumania, having arranged for their settlement with Ivan Asen.
[9][10][11] When the Mongol commander Kadan withdrew from the invasion of Hungary, he entered Bosnia in late March or early April 1242.
In Zeta, however, the forces of Kadan attacked Kotor, razed to the ground Svač and Drisht and probably also destroyed Sapë, which was only rebuilt several decades later.
[15] According to Thomas of Split, a contemporary and partial eyewitness, the Mongols "overran all of Serbia and came to Bulgaria" (totam Serviam percurrentes in Bulgariam devenerunt).
Another contemporary, the archdeacon Roger of Várad from Hungarian Transylvania, notes that "Kadan destroyed Bosnia and the kingdom of Rascia and then crossed into Bulgaria" (Cadan ... destruxit Boznam, regnum Rascie et inde in Bulgariam pertransivit).
It is recorded that in the predominantly Catholic region around Lake Scutari in Zeta she repaired and rebuilt many towns, churches, and monasteries damaged and destroyed by the Mongols in 1242.
[21] A marginal notation in a Greek manuscript in the Vatican Secret Archives notes that it was purchased by a certain Theodore Grammatikos after the Mongol invasion of Bulgaria, in the year 6751 Anno Mundi in the Byzantine calendar.
[22] According to the Persian historian Rashid-al-Din Hamadani, the Bulgarian capital of Tarnovo (Qirqin) and the Black Sea port of Anchialos (Qila) were sacked "after great battles", by which Rashid probably means sieges.
[7][14][16][23] The identification of Rashid's Qila with Anchialos is recent: it has more often been identified with Chilia on the Danube, but this place was not a city worth attacking at the time.
The Andalusian writer Ibn Sa'id al-Maghribi, writing in his Geography in 1250, confirms the Mongol attack on Tarnovo (Arabic Tarnabu).
Archaeological evidence of destruction, including coin hoards, that can be dated to 1242 has been found at Červen, Isaccea, Loveč, Nufăru, Preslav, Silistra, Šumen, Svištov, Turcoaia and Varna, as well as at Tarnovo itself and the island of Păcuiul lui Soare, which was completely destroyed.
[16] According to Thomas of Split, before leaving Bulgaria the Mongols massacred their captives—"Hungarians, Slavs and other peoples"—as they had also done in Croatia in March or April.
Modern historians usually link it to the invasion of 1242,[25] although, as Greg Rogers notes, "an explanation for why only Bulgaria, of all the areas traversed by Batu's troops in 1241 and 1242, became enmeshed in the Mongols' tribute system is still lacking in the historical literature.
In any case, the campaign of 1242 brought the frontier of the authority of the Golden Horde (Batu's command) to the Danube, where it remained for some decades.
[28] Bulgaria as a vassal of the Mongols, provided troops to Mengu-Timur's expedition against the Byzantines in Thracia in 1267[29] and again became a victim of the Golden Horde's incursions in the 1280s.
[30] Bulgaria was still paying tribute into the early second half of the fourteenth century and a considerable part of the Bulgarian kingdom was under direct control of the Chingissid prince Nogai and later the Mongol governors of the Golden Horde.