The "Eternal Edict" was a law passed in 1667, under De Witt's guidance, which aimed to prevent the Prince of Orange from holding the position of Stadtholder, a move to ensure the power remained with the States General and not with a single monarch. This edict was significant as it represented De Witt's republican ideals, emphasizing the distribution of power and the importance of a state governed by laws rather than by royal decree.