In the castle of Caen (Calvados), the second city of Normandy since the 1060s, stands a vast Romanesque hall, once part of the ducal palace, and known since the 19th century as the Échiquier. Long claimed to have had two storeys and to date from the reign of Henry I, it has now been shown on archaeological and structural grounds to have contained a single volume, and can be reattributed, for stylistic reasons, to the end of the 11th century. Given its similarities in form and date to Westminster Hall, and the circumstances surrounding Rufus’s rule in Normandy, it is suggested that the Échiquier was built on his initiative and for a similar purpose. Furthermore, the recent archaeological discovery of a building near the Echiquier, perhaps of the same date and reminiscent of the Lesser Hall at Westminster, suggests that the two hall’s affinity extended to possessing substantial camera-like structures close by.