Constantius' change of mind
And now the Emperor Constantius, feeling some compunctions, returned to himself; and concluding from their conduct towards Euphrates, that their attacks upon the others were of the same kind, he gives orders that the Presbyters and Deacons who had been banished from Alexandria into Armenia should immediately be released. He also writes publicly to Alexandria, commanding that the clergy and laity who were friends of Athanasius should suffer no further persecution. And when Gregory died about ten months after, he sends for Athanasius with every mark of honour, writing to him no less than three times a very friendly letter in which he exhorted him to take courage and come. He sends also a Presbyter and a Deacon, that he may be still further encouraged to return; for he thought that, through alarm at what had taken place before, I did not care to return. Moreover he writes to his brother Constans, that he also would exhort me to return. And he affirmed that he had been expecting Athanasius a whole year, and that he would not permit any change to be made, or any ordination to take place, as he was preserving the Churches for Athanasius their Bishop.
Source: Historia Arianorum (New Advent)