Claude de Mesmes, Count d’Avaux
The Count d’Avaux was an experienced diplomat and high-ranking official who represented France at the Congress of Westphalia from 1644 to 1648, although he was recalled before the peace was signed. He had previously represented France at several places in Italy and helped negotiate a truce between Sweden and Poland at Stuhmsdorf in 1635. In the latter part of the 1630’s, he resided in Hamburg where he negotiated with Johan Adler Salvius to extend the Franco-Swedish alliance until the end of the war, in which he was ultimately successful.
Unlike his colleague Abel Servien, d’Avaux had already been appointed to represent France at the Congress of Westphalia prior to Mazarin‘s coming to power. Also unlike Servien, d’Avaux spoke German and was well-known and -regarded there. The two fell out even before they reached Münster, ostensibly over a farewell speech in The Hague in which d’Avaux urged the Dutch Republic toward toleration of Catholics. D’Avaux is often associated with the traditional Catholic party in France; however, he supported France’s Protestant alliances and its war against the Habsburgs, unlike those labelled “dévot” (the devout party) in historiography. He did support the Catholic party in the Empire’s religious conflict more strongly than Servien, and opposed some of Mazarin and Servien’s demands for territorial annexation. The quarrel between d’Avaux and Servien became a cause célèbre at the congress; it was muted during the presence of the Duke of Longueville, who outranked them both, but soon flared up again after Longueville left. D’Avaux was therefore deprived of the chance to sign the treaty that he had spent so long negotiating.