Marie married Robert de Ferrers, 6th Earl of Derby 1249, Westminster, London, England. Robert (son of William de Ferrers, 5th Earl of Derby and Margaret de Quincy) was born Abt 1239, Tutbury, Staffordshire, England; died Bef 27 Apr 1279; was buried Aft 27 Apr 1279, Stafford, Staffordshire, England. [Group Sheet]