Jacqueline, 1401–36, countess of Hainaut, Holland, and Zeeland (1417–33). The daughter and heiress of William IV, duke of Bavaria and count of Hainaut, Holland, and Zeeland, and of Margaret of Burgundy, Jacqueline was passed over for the succession to the counties on her father's death in 1417 in favor of her uncle, John of Bavaria. Jacqueline married a cousin, John IV, duke of Brabant, nephew of Philip the Good of Burgundy, but found him useless in helping her recover her inheritance and soon left him. She sought refuge in England, where, although her previous marriage had been dubiously annulled, she married (c.1422) Humphrey, duke of Gloucester, the brother of King Henry V. A subsequent invasion of Hainaut (1424–25) proved unsuccessful, and Jacqueline was abandoned by Humphrey and obliged to make peace with Duke Philip the Good of Burgundy, who sought to avenge her repudiation of John IV. Imprisoned at Ghent, she escaped but submitted after a struggle. The treaty of Delft (1428) recognized her as nominal countess and Philip as her administrator and heir. Four years later she attempted in vain to incite a rebellion in Holland against Philip, after which she abdicated her countships in Philip's favor in 1433.