Ecclesiastical Chronicle, Volume 3

And when Aggai heard that Mari was passing through, he could not stay, so he went and preached and brought the good news in the region of Assyria and in all the land of Shinar. They say that in his time, three hundred and sixty churches were built. First, however, he taught the people of Beth-Garmai original: "ܒܝܬ ܓܪܡܝ", after having endured many injuries from them. Then he went to Seleucia, the city of the Persian kings, which King Seleucus—one of the servants of Alexander the Victorious—had built. Another city was built near it, which was named Ctesiphon, just as it is called in the City of the Magi. In the days when he arrived there, one of the city's leaders fell ill with a severe disease. When Mari arrived, he cast the cross of the Life-giver over him.

[The Latin translation confirms the Syriac account: after Aggai's death, Mari preached in Assyria and Shinar. It notes the founding of 360 churches in the East during his time. It describes his ministry in Beth-Garmai, his travel to Seleucia (founded by Seleucus, a servant of Alexander the Great), and his arrival in Ctesiphon, where he healed a nobleman using the sign of the cross.]

A extensive list of episcopal sees in the region of Beth-Garmai is provided, including Schaharkadta, Beth-Soloc (Carcha), Beth-Nicator, Beth-Sori, Ardabad, Dakuka, Laschum, Ariun (later Mahuze), and others, citing Assemani and other historical authorities.