From Wikipedia, which has a rather differnet and well footnoted version -

"Edward Gibbon[22] argued that George, or at least the legend from which the above is distilled, is based on George of Cappadocia,[23][24] a notorious Arian bishop who was Athanasius' most bitter rival. According to Professor Bury, Gibbon's latest editor, "this theory of Gibbon's has nothing to be said for it"."