[5] The "Royal Republic of Naples" was declared, appealing to the protection of France and nominally headed by Guise (entitled doge in imitation of Venice).

In March 1666 the Sacra Rota declared the marriage valid; but the King (and the House of Guise) refused to recognize the decision, thereby preventing Mme de Bossut from receiving any of the late Duke's vast fortune.

Anna Gonzaga described Duke Henri's "good and bad qualities" as follows: Monsieur Guise had the figure, the air and the manners of a hero in a novel, and his entire life bore the mark this character.

Ambition and love dominated his projects, which were so vast that they were Homeric; but with such an illustrious name, heroic valor, and a bit of good fortune, nothing exceeded his hopes.

He was flighty in his attachments, inconstant in his projects, hasty in carrying things out.He died in Paris on 2 June 1664 and was succeeded by his nephew Louis Joseph de Lorraine.