The diocese of Gumal was located in the Mosul district of northern Iraq, not far from the celebrated Jacobite monastery of Mar Mattai. According to Bar Hebraeus, Gumal was 'a large town in the country of Marga, to the northeast of Mount Alpap'. The town is probably connected with the district of Tel Gomel (in Greek, Gaugamela), which gave its name to Alexander the Great’s victory over the Persians at Gaugamela in 333 BC. The battle seems to have been fought at a site close to the modern Assyrian town of Telkepe, in the historic Marga district.