The supposed Roman college is believed to have been invented by the historian of ill-repute, Edward Williams, more generally known as Iolo Morganwg.
[1] The latter is a legendary Breton prince turned High-King of Britain[2] who, despite appearing in the Welsh Triads, is generally accepted as an invention of the 12th century pseudo-historian, Geoffrey of Monmouth.
"[8] In the run up to and after the withdrawal of the Roman legions, Britain suffered incursions of the Irish, Scots and Picts, who raided British settlements, sacking villages and carrying off the inhabitants as slaves.
Morganwg claimed in the Iolo Manuscripts that the college was burnt down in AD 396 by Irish raiders who kidnapped Saint Patrick who was resident there at the time.
[12] What Morganwg described as a refounding of the college is generally accepted by modern historians as the proper original foundation, although probably at a slightly later date, in the early 6th century.