The reign of Ivan III and his successor was plagued by a number of heresies and controversies. One party, led by Nil Sorsky and Vassian Kosoy, called for the secularisation of monastic properties. They were opposed by the influential Joseph of Volotsk, who defended ecclesiastical ownership of land and property. The sovereign's position fluctuated, but eventually he threw his support to Joseph. New sects sprang up, some of which showed a tendency to revert to Mosaic law: for instance, the archpriest Aleksei converted to Judaism after meeting a certain Zechariah the Jew.