 Following the conclusion of the Roman-Sasanian War of 602-628, Athanasius dispatched John to the court of the newly enthroned Sasanian emperor Kavadh II at the imperial capital of Ctesiphon.During his return journey, John travelled to the Monastery of St. Matthew in Mesopotamia and invited five bishops and three monks, including Marutha of Tikrit, to accompany him.John was elected and consecrated Patriarch of Antioch after the death of Athanasius in July 631.