Muscovite–Volga Bulgars war (1376)

Volga Bulgaria, which was at the time an ulus [ru] of the Golden Horde (who had converted to Islam in 1313[1]), was ruled by emir Hassan Khan (in Rus' chronicles Assan) and Horde protégé Muhammad Sultan (Sultan Mahmat).

[2] In 1364, ongoing raids perpetrated by the Mongol-Tatars on Nizhny Novgorod land forced Prince Dmitry Konstantinovich of Nizhny Novgorod-Suzdal to ally with and seek assistance from Dmitri Ivanovich of Moscow.

During the campaign, many villages in Volga Bulgaria were burned and large numbers were slaughtered.

[3] On March 16, the Muscovite–Suzdalian army invaded Volga Bulgaria, leading Hasan Khan to mount a defense.

Hasan Khan ordered a 5,000 ruble payment (2,000 to soldiers and 3,000 to princes and magistrates) to end the attack.