Hilduin IV, Count of Montdidier

Hilduin IV (d. 1063), Count of Montdidier and Lord of Ramerupt, son of Hilduin III, Count of Montdidier, member of the House of Montdidier. Hilduin was also Count of Roucy by virtue of his marriage to the daughter of Ebles I, Count of Roucy.
Little is known about Hilduin despite his many renowned children and grandchildren. Hériman of Tournai records that Philip I of France appointed Hilduin as an ambassador to Rome (date unknown).
Sometime between 1033 and 1054, probably closer to the latter, Hilduin was driven from Montdidier by Count Ralph IV of Valois, who continued to rule it until his death in 1074.
Hildiun married Adelaide (Alice) de Roucy, daughter of Ebles I, Count of Roucy, and Beatrix of Hainaut. They had nine children:
Hilduin was apparently the last Count of Montdidier, the line being continued with the Counts of Roucy.