In 1707 he was superseded in the Volgan provinces by Andrei Matvyeev.
The terror of their name had long preceded them, and Bela, in 1235 or 1236, sent the Dominican monk Julian, by way of Constantinople, to Russia, to collect information about them from the "ancient Magyars" settled there, possibly the Volgan Bulgarians.
The first step making for security was to build a fleet strong enough to provide against the anarchical condition of those parts; but this implied a direct attack not only upon the Crimean khan, who was mainly responsible for the conduct of the Volgan hordes, but upon the khan's suzerain, the Turkish sultan.
In his reign occurred the invasion of Timur (1395), who ruined the Volgan regions, but did not penetrate so far as Moscow.
He stayed at Sarai, their Volgan capital, all the winter, and not only succeeded in obtaining a mitigation of the tribute, but also the abolition of the military service previously rendered by the Russians to the Tatars.