David of Burgundy was bishop of Thérouanne (Terwaan) from 1451. Thanks to a joint effort between the Cods and Burgundy, he was appointed as bishop of Utrecht by the pope. The Utrecht chapters, however, had elected the Hook-favoured provost Gijsbrecht van Brederode as bishop. But Philip the Good forced the Nedersticht to accept David's appointment on 3 August 1456 at the treaty of IJselstein. The Oversticht had to be forcefully convinced as well. Deventer was besieged for five weeks before it surrendered.&lt;br&gt;