The Grand Duchy of Moscow-Volga Bulgars War of 1376 was organized by princes Dmitry Donskoy of Muscovy, and Dmitry Konstantinovich of Nizhny Novgorod-Suzdal. The combined Muscovite–Suzdalian army was led by Moscow Governor Dmitry Mikhailovich Bobrok Volynsky, and Dmitry of Suzdal's sons Vasily and Ivan Dmitriyevich. Volga Bulgaria, which was at the time an ulus of the Golden Horde, was ruled by emir Hassan Khan and Horde protégé Muhammad Sultan.