Analysis of information sources in references of the Wikipedia article "Theophilus (bishop of the Goths)" in English language version.
The first reference to bishops of the Goths are associated with the area of the Black Sea. In 325 the Council of Nicaea was attended by the bishops "Cadmus of Bosporus" and "Theophilus of Gothia"… The location of Gothia is unclear… "Gothia" and "Scythia" could refer either to Crimea of to the left side of the lower Danube.
John Chrysostom, bishop of Constantinople 398–404, consecrated another bishop of Gothia, Unila. Subsequently, when Chrysostom was in exile in 404, he expressed worry that Unila's successor would be consecrated by his, Chrysostom's, Constantinoplitan rival Arsacius. This would lead one to conclude not only that these Gothic bishops were Nicene, but also that they were under the jurisdiction of the bishop of Constantinople.