In French foreign policy the century. XIII establishes the fundamental principles that will then triumph in the following centuries, being perfected, developed, but not modified. It is precisely from Philip Augustus to Louis IX that the various tendencies are in embryo: Mediterranean relations and interests, Atlantic relations and interests. The relations with the English kingdom, with the Iberian kingdoms, with the Italian and Germanic princes are specified in their true nature. Louis IX claimed to have no other policy than the defense of justice and peace, gathering all the principles in the agreed understanding for the resumption of the crusade against the infidels. But even this activity served to affirm in the French monarchy the claim of wanting to be the supreme guide of European Christianity, replacing the Germanic empire, which ruined through the struggles with the papacy and the great vassals. The two crusades of Louis IX, the first in Syria and Egypt, the second in Tunisia, highlight the hegemonic tendencies of France for dominance in the Mediterranean. The papacy remained on good terms with the various French kings of the thirteenth century. Not even the defiant attitude assumed by Philip Augustus (v.), Who, having repudiated his Ingeburg wife of Denmark, passed on to new illicit marriages, and resisted protests and interdictions for twenty years, could push the papacy to a decisive action.
It is that the popes involved in the struggles with the emperors needed the powerful kings of France. Philip Augustus with independent judgment in turn intervenes in the competition between Philip of Swabia and Otto of Brunswick, in favor of the former and against the latter, who is also supported by the pope. Later Innocent III adopted the anti-Ottonian French policy and Frederick II was hired to the empire under the dual protection of the pope and the king of France. Thus the French monarchy begins its policy of meddling in Germany’s internal politics.
When the conflict between the papacy and the empire re-opened, Louis IX acted with the utmost prudence. Respectful of religion, he rejects the pope’s requests, but is cold but courteous towards the emperor. His crusade program allowed him to avoid dangerous engagements. When Frederick II was thinking of capturing Innocent IV in Lyons, he inquired of the king’s ideas and, knowing him hostile, did not insist. The crisis of the empire after the death of Frederick II excited the French aspirations for dominance; in 1273 there was talk of presenting the candidacy of the king of France, Philip III, to the empire, an indication of the monarchy’s claims to become the center of catholicity. And the demands reappeared again in the following century.
According to ETHNICITYOLOGY, the battle of Bouvines begins a new phase in Franco-English relations: now it is France that hints at lively anti-English action. Philip Augustus seems to have already thought about annexing England: remaking the empire of the Atlantic, but from Paris. His son Luigi had married Bianca di Castiglia, granddaughter of Giovanni Senzaterra and had the opportunity to assert rights to the English crown. In 1215 the negotiations with a group of English feudalists fighting with their king seemed successful; Prince Louis was proclaimed king of England and hastened to organize an expedition. In 1216 he was able to solemnly enter London and have there the homage of the bishops and nobles. But the death of the competitor Giovanni Senzaterra favored the concentration of the English around the legitimate King Henry III, which was also recognized by the pope, eager to prevent the excessive power of France. The policy of Louis VIII was abandoned by Louis IX, who after rejecting the various attempts made by Henry III to regain the possessions of France, preferred to come to a cordial agreement. With the treaty of 1258 Henry III definitively renounced Normandy, Anjou, Touraine, Poitou, but he obtained some lands in the south in restitution, on condition of declaring himself a vassal of the king of France for what he possessed on the continent. Also in other foreign matters of great interest to the reign Louis IX assumed a peaceful attitude. In Flanders succession disputes were repeatedly settled in order to divide Flanders from Hainaut, thereby weakening this great fiefdom in favor of the kingdom. With the treaty of Corbeil the discussions with the kingdom of Aragon were liquidated, which renounced all claims in the Languedoc, excluding Montpellier, while the king of France abandoned the Carolingian claims to the counties of Barcelona and Roussillon (1258). Politics of arbiter and ruler wisely carried out the kings in the Rhine territories of imperial law.
Instead Louis IX himself did not oppose, on the contrary he favored the expedition of Charles of Anjou in the kingdom of Naples, which was the first military action of the Capetian monarchy outside the French territory. Probably in Paris it was thought that the occupation of southern Italy and Sicily was useful for the crusade projects in Egypt and Africa that were dear to Louis IX. Certainly the pontifical proposals were discussed and accepted by Louis IX. The Angevin expedition to Italy exerted a great influence on the French public spirit. Not only was there a current of noble emigration in Italy, but hegemonic tendencies were strengthened in the conviction of the absolute superiority of the French people. The new reign of Philip III (1270-1285) already reveals the victory of these aspirations which they had been wisely contained by Louis IX. The king intervenes in Navarre to defend the interests of those princes linked with the French dynasty against the Castilian and Aragonese dynasties and succeeds in marrying the heir of that kingdom with a son of Philip III; intervenes in Castile in the bitter battle of the Infanti della Cerda. But above all lively is the action against the great monarchy of Aragon, which develops an important military activity in the Mediterranean, aimed at crumbling the Angevin state of Sicily. It is thought to respond to the Sicilian Vespers by occupying Aragon in agreement with the papacy: in 1285 a large army crosses the Pyrenees and begins the conquest, which however fails. Thus also in the relations of England an attempt is made to abandon the peaceful policy of Louis IX; and when Alfonso of Poitiers died, the royal officials occupied all the territories of the prerogative, without worrying about the rights that the treaty of 1258 gave to the king of England. Only in 1279 was an agreement reached, giving the bishopric of Agen to the opponent.