This leaf can be dated to ca. 1500.
This initial begins the Introit for the feast of St. Michael (Sept. 29), "Benedicite dominum omnes angeli eius ..." (Bless the Lord, all you angels of his). Lewis E M 66:13-14 are from the same manuscript. This leaf was illuminated by an assistant of Cornelia van Wulfschkercke, a nun at the Bruges Carmelite convent Sion who was active in the late 15th and early 16th century. The other leaf is by her hand.
Initial B with St. Michael Archangel Conquering the DevilView full details.