The Corsican Guard Affair was an event in French and papal history, illustrating Louis XIV of France's will to impose his power on other European leaders.
De Créquy was sent to Rome by Louis as ambassador extraordinary to put an end to the conflict between the cardinal and the papal guards and so he was accompanied by several soldiers.
The situation broke down when the duke's soldiers passed through a tobacco shop and reviled two Corsican guards in a Roman cabaret.
The papal legate, cardinal Chigi, appeared before Louis on 29 July 1664 and publicly apologised for the incident, on which France returned Avignon to the pope.
The incident was commemorated by a tapestry now on show at the château de Fontainebleau, a section of the ceiling of the Hall of Mirrors in Versailles, and a bronze medallion from a side lantern of the Louis XIV Victory Monument which is now kept at the Louvre.