Death of Athanasius, and Elevation of Peter to His See
It must be said that as long as Athanasius, bishop of Alexandria, was alive, the emperor, restrained by the Providence of God, abstained from molesting Alexandria and Egypt: indeed he knew very well that the multitude of those who were attached to Athanasius was very great; and on that account he was careful lest the public affairs should be hazarded, by the Alexandrians, who are an irritable race, being excited to sedition. But Athanasius, after being engaged in so many and such severe conflicts on behalf of the church, departed this life in the second consulate of Gratian and Probus, having governed that church amidst the greatest perils forty-six years. He left as his successor Peter, a devout and eloquent man.
Source: Ecclesiastical History (New Advent)