The main text in CCCC MS 455 is the Summa de arte praedicandi of Thomas of Chobham (d. after 1233), subdean of Salisbury Cathedral and also known as Thomas of Salisbury. This is a treatise on preaching, and it is followed by Thomas's sermon for Palm Sunday (Sermo XXIII). At the end of the manuscript there are antiphons for St Edmund the Martyr with musical notation on a four-line stave, and also a few charms. The book was written in the thirteenth century.