William I, Count of Holland Count of Holland from 1203 to 1222 (1167–1222) Parents Ada of Huntingdon Floris III Children Otto III van Holland Ada of Holland Floris IV, Count of Holland Siblings Florence of Holland Dirk VII, Count of Holland Ada of Holland Margareta van Hollant Mechtild zu Styrum Boudewijn Agnes van Hollant Partners Maria of Brabant Adelaide of Guelders
