The Capetian dynasty has long enjoyed a reputation for brilliance in the forging of an image of kingship. From the earliest years of political weakness, the family had striven to elevate its status by casting kingship in a sacral aura. It might therefore seem pointless to speculate that the French kings could owe anything to their cousins in the Regno, who after all only obtained their crown during the reign of St Louis, the king noted for doing more than any other French ruler to enhance the reputation of the office he fulfilled. Yet there is at least one aspect of thinking about later medieval French kingship which was consciously formed by Charles of Anjou, and which came to have a profound effect on later generations: that of the beata stirps (saintly lineage). Since Charles was already king of the Regno before any sign of this development appeared, it seems reasonable to ascribe it to his experience beyond the borders of France, and to the connections his family had made with the Hungarian royal family, where beata stirps was already well entrenched.

In 1269, Charles began negotiations with Stephen V of Hungary to secure a double marriage with the Hungarian royal family; his eldest son Charles was to marry Maria, Stephen's daughter, and Stephen's son Ladislas – the future Ladislas IV – was to marry Charles's daughter Isabelle. In defence of his choice, Charles described Stephen as ‘a valiant, strong prince, descended from a line of saints and great kings’.