The paxs reverse is customarily interpreted as a form of the Latin word pax, ‘peace’. Previous coins that feature the paxs legend were struck at the beginning of the reigns of Edward the Confessor and Harold II. As this paxs penny featured at the end of the reign of William I it has been argued that the coin is in fact from the beginning of his son’s reign to reiterate the coronation oath to keep the king’s peace.