Brief accounts of Giwargis's patriarchate are given in the Ecclesiastical Chronicle of the Jacobite writer Bar Hebraeus (floruit 1280) and in the ecclesiastical histories of the Nestorian writers Mari (twelfth-century), ʿAmr (fourteenth-century) and Sliba (fourteenth-century); also, in veiled and biased form, John bar Penkaye (fl.
Thomas drew on a lost ecclesiastical history of the Church of the East written by Athqen, a monk of the monastery of Mar Abraham on Mount Izla.
In the time of Giwargis the doctor Yohannan, bishop of Beth Waziq, cut off his members after he was accused of fornication, and was then condemned all the more and deposed.
[2] Also of his time, John bar Penkaye wrote: "This period of calm was to us the cause of so much weakness, that there happened to us what happened to the Israelites, of whom it is said: "Israel has grown fat and lazy, he has become fat and wealthy, he has abandoned the God who made him, and despised the strong one that saved him."
""[3]Bar Penkaye specifically hits "the leaders" under Muawiyah - which can only be Giwargis - for arrogance, for greed, for gluttony, for involvement in politics, and for bribing the secular authorities (also applicable to Ishoyahb III).