The general peace treaty was signed and proclaimed at Le Cateau on 3 April 1559. The day before, Sansac, the governor of Picardy, announced the news to Amiens and on 7 April a great service in the cathedral was followed by a general procession. On 5 April the king had issued from Coucy a manifesto against the robberies and exactions of his soldiers, committed to his ‘trèsgrand regret’, in terms that echoed the denunciations of military abuses throughout the wars. The demobilisation of forces was not markedly different from that following earlier treaties: reductions in garrisons took place only in stages and work on fortifications was slowed down over the course of 1559. In April 1559, there could have been little to indicate that this was any more than another pause in the seemingly endless dynastic wars.

Two factors in reality turned the treaty of 1559 into something different: first, the financial exhaustion which had pushed both sides to the conference table remained a determinant; secondly, the far-reaching political upheavals in France stemming from the sudden death of Henri II froze the international compromise. That monarch had made known as soon as the treaty was sealed his desire to deal conclusively with heresy, but similar plans had been envisaged in 1544–5 and had come to nothing. The preparation of an antiheresy campaign was more dangerous, of course, in the context of 1559 and gave rise to extreme reactions, but it was the king's death that released a naked struggle for power.