In 361, after the death of Emperor Constantius, shortly followed by the murder of the very unpopular Bishop George, Athanasius returned to his patriarchate. The following year he convened a council at Alexandria, and presided over it with Eusebius of Vercelli. Athanasius appealed for unity among all those who had faith in Christianity, even if they differed on matters of terminology. This prepared the groundwork for his definition of the orthodox doctrine of the Trinity. However, the council also was directed against those who denied the divinity of the Holy Spirit, the human soul of Christ, and Christ's divinity. Mild measures were agreed on for those heretic bishops who repented, but severe penance was decreed for the chief leaders of the major heresies.

Answer this question, if possible (if impossible, reply "unanswerable"): When did Athanasius return to his position as Patriarch?
after the death of Emperor Constantius