Mathilda of Flanders died on November 2, 1083. Her illness must have lasted only a matter of months as she was active in mid-July of that year. According to Orderic Vitalis, she fell ill sometime in September and her condition rapidly declined. It is possible that Abbot Baldwin of Bury St Edmunds treated her as he was in Caen at the time. If so, he was unable to improve her health. Orderic reported that her death was mourned for many days in Normandy and England. Both Orderic and William of Malmesbury indicate she was celebrated with a lavish funeral.

Mathilda was interred at Holy Trinity, Caen just as she intended, her body placed between the choir and the altar. Orderic attests that many archbishops, bishops and abbots were present for the ceremony, as well as monks, nuns and ‘a great throng of poor people’. Mathilda was set beneath an elaborate black Tournai marble monument covered in gold and jewels, decorated with a golden efgy. Orderic records her epitaph, carved in gold, which celebrates her bloodline, her piety and her foundation of Holy Trinity (Plate 7).