Richilde may have been a daughter of Reinier of
Hasnon (died c. 1049) and Adelheid of
Egisheim. She was born c. 1018. In 1040, she married
Herman of Mons, who became
Count of Hainaut. As Hainaut and Valenciennes were imperial fiefs and
Henry III, Holy Roman Emperor had not been consulted, the marriage resulted in a war between the emperor and the Baldwins, ending in a total defeat of the latter in 1054. But still Richilde's husband Baldwin became ruling count of Hainaut
jure uxoris and the two children she had with Herman were disinherited. Roger, probably lame, became a secular clerk (later
Bishop of Châlons-sur-Marne) and her daughter a nun. Baldwin VI also obtained assurances from his brother
Robert who gave his oath of homage and promised to protect his nephew. Almost immediately,
Robert broke his oath and disputed Arnulf's right to Flanders. Richilde obtained support from King
Philip I of France.
William FitzOsbern of Normandy (who married her) also assisted her in the conflict, but likely with a very small contingent. However, her forces were defeated at the
Battle of Cassel and
William FitzOsbern was killed along with her oldest son, Arnulf. Richilde herself was captured and released, and King Philip later married Robert's stepdaughter Bertha and recognized him as Count of Flanders, abandoning the cause of Richilde and her son. Richilde built the
Château de Beaumont along with a chapel there dedicated to
St. Venantius. At the end of her regency she retired to the
Abbey of Messines. ==Family==