During the Mongol invasion of Europe, Mongol tumens led by Batu Khan and Kadan invaded Serbia and then Bulgaria in the spring of 1242 after defeating the Hungarians at the battle of Mohi and ravaging the Hungarian regions of Croatia, Dalmatia and Bosnia.
Initially, the troops of Kadan moved south along the Adriatic Sea into Serbian territory. Then, turning east, it crossed the centre of the country—plundering as it went—and entered Bulgaria, where it was joined by the rest of the army under Batu. The campaigning in Bulgaria probably happened mainly in the north, where archaeology yields evidence of destruction from this period. The Mongols did, however, cross Bulgaria to attack the Latin Empire to its south before withdrawing completely. Bulgaria was forced to pay tribute to the Mongols, and this continued thereafter.