John IV of Brabant

John IV married Jacqueline of Hainaut to gain control of her counties of Holland, Zeeland, and Hainaut. The marriage was intended to strengthen his position but instead embroiled him in the Hook and Cod wars.

Under pressure from his advisors and Philip the Good, John IV abandoned his wife Jacqueline's claims to Holland and Hainaut. This betrayal led to the collapse of their marriage and left Jacqueline isolated.

John IV's weak rule led to the Estates of Brabant inviting Philip the Good of Burgundy to take over governance. John IV was effectively sidelined, and Brabant came under Burgundian influence.