Being an ally of Volga Bulgaria, he resisted easterly Slavic expansion of Suzdalian Rus forces into the region.

Then Purgaz defeated the Mokshan prince, Puresh[1] In April, 1229 he tried to regain Nizhny Novgorod from the hands of Zalesyean Rus', which was formerly the Erzyan settlement of Obran Osh.

During Purgaz's reign his land noted an influx of Ruthenian Slavic peasants into it.

In the summer of 1237, he successfully resisted the advance of the Mongols, he was defeated between the autumn of 1238 and the winter of 1239.

Since the 13th century, Purgaz had been idolized as a mythical hero; he started to be erroneously called a King of Mordovia.