Montaigne argues that is right and proper for a people to speak ill of a “faulty prince” after his death (1580)

Amongst those laws that relate to the dead, I look upon that to be very sound by which the actions of princes are to be examined after their decease. They are equals with, if not masters of the laws, and, therefore, what justice could not inflict upon their persons, ’tis but reason should be executed upon their reputations and the estates of their successors—things that we often value above life itself. ’Tis a custom of singular advantage to those countries where it is in use, and by all good princes to be desired, who have reason to take it ill, that the memories of the wicked should be used with the same reverence and respect with their own. We owe subjection and obedience to all our kings, whether good or bad, alike, for that has respect unto their office; but as to esteem and affection, these are only due to their virtue. Let us grant to political government to endure them with patience, however unworthy; to conceal their vices; and to assist them with our recommendation in their indifferent actions, whilst their authority stands in need of our support. But, the relation of prince and subject being once at an end, there is no reason we should deny the expression of our real opinions to our own liberty and common justice, and especially to interdict to good subjects the glory of having reverently and faithfully served a prince, whose imperfections were to them so well known; this were to deprive posterity of a useful example.