However, the Palace Law was not always followed and did not ensure smooth successions. At least one third of Ayutthaya's royal successions involved bloodshed. Indeed, the history of the kingdom at that time is a chronicle of frequent usurpations and of ambitious men thwarting the final wishes of recently departed kings. Historian David K. Wyatt observed that "virtually all successions to the throne of Ayutthaya in the seventeenth and eighteenth centuries were, at the least, irregular, and in many cases either disguised or real usurpations."