Complex sentence: According to Alban Butler, the abbey was given by Charlemagne to Alcuin and functioned as a hostel for those crossing the English Channel; it became a centre of pilgrimage, especially popular with Flemish and Germans in the fourteenth and fifteenth centuries.
Split into simpler sentences: According to Alban Butler, Charlemagne gave the abbey to Alcuin who turned it into a hostel for those crossing the English Channel. It later became a site of pilgrimage, especially popular with Flemish and Germans in the fourteenth and fifteenth centuries.