[1] What started as the "Chapelle du Folgoët" originated in the reign of John IV, the foundations being laid from 1350 to 1360 but it was during the reign of John V, Duke of Brittany that real progress was made between 1420 and 1422 and in 1423, the Duke founded the chapel college.
This is marked by an inscription over the west porch reading "JOHAANES ILLVSTRISSIMVS DVX B(R)ITONVM FVNDAVIT PRAESZE(N)S C(OL)LEGIVM ANNO D(OMI)NI.CCCC.XX.111".
This entrance features three of the bishops mentioned below and a tympanum with a depiction of the Virgin Mary with child.
There is a sculpture depicting Saint Michael fighting the dragon to the left of the west porch entrance.
Inside the church are statues by the atelier of John the Evangelist, John the Baptist, Margaret the Virgin and Catherine of Alexandria, and the "Autel des Anges" (the altar of the angels) decorated with carvings of angels.
The fountain has its source beneath the main altar inside the basilica and it emerges by the chevet.