Chains of Folly by Roberta Gellis

The body of a woman is found in the bishop of Winchester's bedchamber, with a letter from the king's enemy. The obvious purpose is to embarrass the bishop and punish him for daring to criticize the king for his high-handed treatment of the bishop of Salisbury. Winchester's knight, Sir Bellamy of Itchen, along with Magdalene la BГўtarde, whoremistress of the Old Priory Guesthouse must discover the truth. 4th Magdalene la BГўtarde Medieval Mystery by Roberta Gellis; originally published by Five Star