In the chapter on visitors to the Regno, it was stressed that the great majority of those Frenchmen about whom we know something came south for purposes of fighting, whether by way of religious obligation or in order to get valuable military experience. During the whole of the period 1266 to 1302, there were in southern Italy and Sicily either rebellions to be suppressed or wars against the Greeks or the Aragonese to be prepared for and then fought. Charles of Anjou was the most admired military leader of his age. To take service under him – or to a lesser extent under his successor Robert d'Artois – was to acquire skills and also reputation that would stand a man in good stead once he had returned home. (It follows that, after Robert d'Artois went back to France in November 1291, fighting in the Regno lost some of its appeal to French soldiers.)

Gathering an army to fight far from home involved organisation and paperwork that attacking one's neighbour in France did not. Methods of recruitment to the crusades of Outremer had changed vastly over the nearly two centuries between the first crusade of 1097–1100 and the Tunis crusade of Louis IX in 1270. By the time Louis IX planned his second expedition, he appreciated that he needed to be surrounded by men on whose loyalty he could rely, who were also trained in the arts of warfare.