Despite his preoccupation with Italy and Germany, the early years of Innocent's pontificate saw him busily engaged in upholding the papal authority and the moral order of the Church in every country in Europe. No consideration of the immediate interests of the Roman see ever prevented him from maintaining his principles even against powerful sovereigns who could do much to help forward his general plans. The most conspicuous instance of this was Innocent's famous quarrel with Philip Augustus of France, when to vindicate a simple principle of Christian morals he did not hesitate to abandon the alliance of the "eldest son of the Church" at a time when the fortunes of the papacy were everywhere doubtful. Philip's first wife, Isabella of Hainault, the mother of the future Louis VIII, had died in 1190, just before her husband had started on his crusade. In 1193 Philip negotiated a second marriage with Ingeborg, the sister of Canute VI, the powerful King of Denmark, hoping to obtain from his Danish brother-in-law substantial help against England and the Empire. Philip did not get the expected political advantages from the new connection, and at once took a strong dislike to the lady. On the day after the marriage Philip refused to have anything more to do with his bride. Within three months, he persuaded a synod of complaisant French bishops of Compiègne to pronounce the marriage void by reason of a remote kinship that existed between the two parties.
Ingeborg was young, timid, friendless, helpless, and utterly ignorant of the French tongue, but King Canute took up her cause, and, from her retreat in a French convent, she appealed to Rome against the wickedness of the French King and clergy. Celestine III proved her friend, and finding protestations of no avail, he finally quashed the sentence of the French bishops and declared her the lawful wife of the French King. But Philip persisted in his repudiation of Ingeborg, and Celestine contented himself with remonstrances and warnings that were utterly disregarded. In 1196 Philip found a fresh wife in Agnes, a lady of the powerful house of Andechs-Meran, whose authority was great in Thuringia, and whose Alpine lordships soon developed into the country of Tyrol.
Innocent at once proved a stronger champion of Ingeborg than the weak and aged Celestine. He forthwith warned Philip and the French bishops that they had no right to put asunder those whom God had joined together. "Recall your lawful wife," he wrote to Philip, "and then we will hear all that you can righteously urge. If you do not do this, no power shall move us to right or left, until justice be done." A papal legate was now sent to France, threatening excommunication and interdict, were Ingeborg not immediately reinstated in her place. For a few months the Pope hesitated, moved, no doubt, by his Italian and German troubles, and fearful lest his action against a Christian prince should delay the hoped-for crusade. But he gradually turned the leaders of the French clergy from their support of Philip, and at last, in February, 1200, an interdict was pronounced forbidding the public celebration of the rites of the Church in the whole lands that owed obedience to the King of France.
Philip Augustus held out fiercely for a time, declaring that he would rather lose half his lands than be separated from Agnes. Meanwhile he used pressure on his bishops to make them disregard the interdict, and vigorously intrigued with the cardinals, seeking to build up a French party in the papal curia. Innocent so far showed complacency that the legate he sent to France was the King's kinsman, Octavin, Cardinal-bishop of Ostia, who was anxious to make Philip's humiliation as light as possible. His labors were eased by the partial submission of Philip, who in September visited Ingeborg, and promised to take her again as his wife, and so gave an excuse to end the interdict. Philip still claimed that his marriage should be dissolved; though here again he suddenly abandoned a suit which he probably saw was hopeless. The death of Agnes of Meran in July, 1201, made a complete reconciliation less difficult. Next year the Pope legitimated the children of Agnes and Philip, on the ground that the sentence of divorce, pronounced by the French bishops, gave the King reasonable grounds for entering in good faith on his union with her. Ingeborg was still refused the rights of a queen, and constantly besought the Pope to have pity on her forlorn condition. The Pope was now forced to content himself with remonstrances. Philip declared that a baleful charm separated him from Ingeborg, and again begged the Pope to divorce him from a union based on sorcery and witchcraft.
The growing need of the French alliance now somewhat slackened the early zeal of Innocent for the cause of the Queen. But no real cordiality was possible as long as the strained relations of Ingeborg and Philip continued. At last, in 1213, in the very crisis of his fortunes, Philip completed his tardy reconciliation with his wife, after they had been separated for twenty years. Henceforth Philip was the most active ally of the papacy.
While thus dealing with Philip of France, Innocent enjoyed easier triumphs over the lesser kings of Europe. It was his ambition to break through the traditional limits that separated the church from the state, and to bind as many as he could of the kings of Europe to the papacy by ties of political vassalage. The time-honored feudal superiority of the popes over the Norman kingdom of Sicily had been the first precedent for this most unecclesiastical of all papal aggressions. Already others of the smaller kingdoms of Europe, conspicuous among which was Portugal, had followed the example of the Normans in becoming vassals of the holy see. Under Innocent at least three states supplemented ecclesiastical by political dependence on the papacy. Sancho, King of Portugal, who had striven to repudiate the former submission of Alfonso I, was in the end forced to accept the papal suzerainty. Peter, King of Aragon, went in 1204 to Rome and was solemnly crowned king by Innocent. Afterward Peter deposited his crown on the high altar of St. Peter's and condescended to receive the investiture of his kingdom from the Pope, holding it as a perpetual fief of the holy see, and promising tribute to Innocent and his successors. In 1213 a greater monarch than the struggling Christian kings of the Iberian peninsula was forced, after a long struggle, to make an even more abject submission.
The long strife of Innocent with John of Anjou, about the disputed election to the see of Canterbury, was fought with the same weapons which the Pope had already employed against the King of France. But John held out longer. Interdict was followed by excommunication and threatened deposition. At last the English King surrendered his crown to the papal agent Pandulf, and, like Peter of Aragon, received it back as a vassal of the papacy, bound by an annual tribute.
Nor were these the only kings that sought the support of the great Pope. The schismatic princes of the East vied in ardor with the Catholic princes of the West in their quest of Innocent's favor. King Leo of Armenia begged for his protection. The Bulgarian prince John besought the Pope to grant him a royal crown. Innocent posed as a mediator in Hungary between the two brothers, Emeric and Andrew, who were struggling for the crown. Canute of Denmark, zealous for his sister's honor, was his humble suppliant. Poland was equally obedient. The Duke of Bohemia accepted the papal reproof for allying himself with Philip of Swabia.
Despite his vigor and his authority, Innocent's constant interference with the internal concerns of every country in Europe did not pass unchallenged. Even the kings who invoked his intercession were constantly in conflict with him. Besides his great quarrels in Germany, France, and England, Innocent had many minor wars to wage against the princes of Europe. For five years the kingdom of Leon lay under interdict because its king Alfonso had married his cousin, Berengaria of Castile, in the hope of securing the peace between the two realms. It was only after the lady had borne five children to Alfonso that she voluntarily terminated the obnoxious union, and Innocent found it prudent, as in France, to legitimize the offspring of a marriage which he had denounced as incestuous. Not one of the princes of the peninsula was spared. Sancho of Navarre incurred interdict by reason of suspected dealings with the Saracens, while the marriage of his sister with Peter of Aragon, the vassal of the Pope, involved both kings in a contest with Innocent. Not only did the monarchs of Europe resent, so far as they were able, the Pope's haughty policy; for the first time the peoples of their realms began to make common cause with them against the political aggressions of the papacy. The nobles of Aragon protested against King Peter's submission to the papacy, declared that his surrender of their kingdom was invalid, and prevented the payment of the promised tribute. When John of England procured his Roman overlord's condemnation of Magna Charta, the support of Rome was of no avail to prevent his indignant subjects combining to drive him from the throne, and did not even hinder Louis of France, the son of the papalist Philip II, from accepting their invitation to become English king in his stead. It was only by a repudiation of this policy, and by an acceptance of the Great Charter, that the papacy could secure the English throne for John's young son, Henry III, and thus continue for a time its precarious overlordship over England.
For the moment Innocent's iron policy crushed opposition, but in adding the new hostility of the national kings and the rising nations of Europe to the old hostility of the declining empire, Innocent was entering into a perilous course of conduct, which, within a century, was to prove fatal to one of the strongest of his successors. The more political the papal authority became, the more difficult it was to uphold its prestige as the source of law, of morality, of religion. Innocent himself did not lose sight of the higher ideal because he strove so firmly after more earthly aims. His successors were not always so able or so high-minded. And it was as the protectors of the people, not as the enemies of their political rights, that the great popes of the eleventh and twelfth centuries had obtained their wonderful ascendency over the best minds of Europe.