Kathryn Warner, The Amatory Adventures of John de Warenne. "But the main subject of this post is Edward II's niece Jeanne de Bar and her husband John de Warenne, their spectacularly awful marriage, John's numerous illegitimate children, his high-born mistresses, and his unsuccessful-but-decades-long attempts to divorce Jeanne, which culminated in his amusingly implausible claim that he'd had an affair with Edward II's sister Mary, a nun." Blog Kathryn Warner.