On this day in 1265, Henry III and his son Lord Edward stood in the chapter house of Westminster Abbey, which near the floor bears the appropriate inscription ‘As the rose is the flower of flowers’, and swore to abide by all the charters of good government, namely Magna Carta and the Provisions of Oxford as embodied in the current constitution. It was a momentous step, the first time the king is promising to rule in accordance with established laws and institutions without getting anything in return, and he was passing on the precedent directly to the heir to the throne. Of course, both were more or less captive at the time and neither had shown any inclination in the past to show that their word was worth much. In those days you could swear to god all you wanted so long as as the pope was in your pocket.
