Gregory spent the next few years combating Arianism, which threatened to divide the region of Cappadocia. In this tense environment, Gregory interceded on behalf of his friend Basil with Bishop Eusebius of Caesarea (Mazaca). The two friends then entered a period of close fraternal cooperation as they participated in a great rhetorical contest of the Caesarean church precipitated by the arrival of accomplished Arian theologians and rhetors. In the subsequent public debates, presided over by agents of the Emperor Valens, Gregory and Basil emerged triumphant. This success confirmed for both Gregory and Basil that their futures lay in administration of the Church. Basil, who had long displayed inclinations to the episcopacy, was elected bishop of the see of Caesarea in Cappadocia in 370.