Sometime in the period 1093–1100, he and his wife, Maud, founded the Priory of St Andrew's, Northampton.
[1] Simon de Senlis subsequently went abroad and died at La Charité-sur-Loire, where he was buried in the new priory church.
Simon was the third son of Laudri de Senlis, sire of Chantilly and Ermenonville (in Picardy), and his spouse, Ermengarde.
This Judith had earlier refused to wed Simon; she had fled abroad to avoid her uncle's wrath.
David was recognized as Earl of Huntingdon to the exclusion of his step-son, Simon; the earldom of Northampton reverted to the crown.