Agnès de Dammartin (died 1227) (d. 1227) Parents Mahaut de Clermont Alberic III of Dammartin Children unknown daughter de Fiennes Mahaut de Fiennes, Dame de Heuchin Siblings Aelis de Dammartin Julia de Dammartin Simon, Count of Ponthieu Renaud I, Count of Dammartin Partners Guillaume I de Fiennes, Seigneur de Fiennes