Waltrude persuaded Saint Ghislain to establish an oratory at a place called Ursidongus, now known as Saint-Ghislain.

Hydulphe of Hainault, husband of her cousin Aye, built her a cell and chapel near Ghislain's oratory.

When the captives had been bought back with the ransom money out of her own purse, at her command they returned to their families and homes.

"[6] Upon her death, established by tradition as falling on 9 April 688, Waltrude was proclaimed holy by the vox populi.

Each year, as part of the Ducasse de Mons festival, the shrine is placed on the car d'or, a gilded cart, and drawn by horses through the city streets.