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), Amr (fourteenth-century) and Sliba (fourteenth-century); also, in veiled and biased form, John bar Penkaye (fl.
A fuller account of the reign of Giwargis, describing in detail his quarrel with the metropolitan Giwargis of Nisibis, who opposed his election, is given by Thomas of Marga in his Book of Governors.