Complex sentence: Nothing is known about Felix, although Bertram Colgrave has observed that he was a good scholar who evidently had access to works by Bede and Aldhelm, to a "Life" of Saint Fursey and Latin works by Saint Jerome, Saint Athanasius and Gregory the Great.
Split into simpler sentences: Nothing is known about Felix, although Bertram Colgrave has observed that he was a good scholar who was familiar with the works of Bede and other writings, such as those of Aldhelm. Felix evidently had access to works by Bede and Aldhelm, of a "Life" of Saint Fursey and of Latin works by Saint Jerome, Saint Athanasius and Gregory the Great.