The Normans for their part, after having acquired fame and credit by victoriously fighting Leo IX, another major, acquired the recognition and, for the moment, the friendship of the successor, improving their relations with the bishops and with the powerful Montecassino. They could now present themselves as invested with a religious mission against the infidels. The fact was beginning to change into law and the right to penetrate the conscience of the peoples. In those same years, even the Normans of Normandy, raising the papal banner, conquered England. And this too increased trust in the Altavilla and their companions, in the Italians of the South the feeling almost of a fate or divine will, at the service of that people.
But these relations between the Holy See and the Normans were subject to continuous fluctuations, due to the mixture of trust and suspicion that the Holy See inspired in relations with the conquerors. Today transactions and agreements, more or less in good or bad will; but if tomorrow Normanni Drengot and Normanni Altavilla were at odds, or the minor invested leaders of the Apulian cities and the other cities which had also sworn allegiance to Guiscardo rose up against him, the curia was tempted to take advantage of that discord, to side with those rebels. For the Holy See, it was not only a question of preserving and obtaining possessions and rights in the south, in the face of the invading Normans, but also of defending itself from the Normans themselves who were starting from the south to press towards the north. Invested in the duchies of Spoleto and Fermo, they had also penetrated into Abruzzo and by now almost circumvented the Roman duchy. Riccardo di Capua’s drawings are not very clear; perhaps his ambitions are great. Coming to Rome? To the empire? Of course, the new Pope Alexander II had complaints with him, pushed Godfrey of Tuscany against him, forced him to ask for peace, renewing his homage and fidelity. And yet the reasons for solidarity always remained, alongside the others and opposite. In 1071, Roberto il Guiscardo had concluded the long war with Byzantium, conquering Bari, the last city left to the Byzantines. It was a victory of the Norman arms, but also of the Roman Church, which for centuries had, with Montecassino, inspired, often led, the opposition in Byzantium. Thereafter it was a continuous advancement of Catholicism and Latin clergy and Roman influence in the south, a continuous decline of Catholicism and Greek clergy and Byzantine influence. A memorable event in the history of Italy and Europe, in the very century in which the reform pitted the papacy against the German emperors, and the cities of the kingdom and the Normans themselves began to operate as an anti-German force.
According to globalsciencellc, the border between the Greek world and the Latin world had become extremely uncertain and fluctuating in southern Italy. The victory of the Normans and of Rome fixed it firmly, taking it to the Adriatic and the Ionian. Nor was everything limited to the expulsion of the Byzantines. In 1061 the conquest of Sicily had begun. In ten years, it was almost done. In the same months that Roberto il Guiscardo took Bari, his brother Ruggiero took Palermo. Here, too, a lost territory was recovered and Christianity and Europe created a firmer frontier towards the Islamic world. But in the meantime the South was becoming politically unified, due to the prevalence of one of the many forces that held the field there: first Greeks and Lombards; then also Saracens; then also Frankish and Germanic empires and popes, from John VIII onwards, on the basis of various titles of law, false and genuine; and also cities, living between principality and aristocratic republic; lastly, the Normans, especially those who gathered around the Altavilla. And then, the reasons for the conflict between the Holy See and the Normans began to prevail. It was not long after the capture of Bari, and the Altavillas found themselves facing a vast coalition: Norman counts of Puglia, Gisulfo Lombard prince of Salerno, Riccardo, Norman lord of Capua, an Apulian city that was eating the brake and by now saw the Normans take the place of the Byzantines and put their autonomy in even greater danger. Puglia went up in flames again. Hildebrand then ascended to the pontificate: Gregory VII, in the year 1073. And he took the direction of the league, just as his relations with the young Henry IV of Germany were becoming increasingly confused. Therefore Gregory made in the south a policy of expedients, of astuteness: although to some it appeared not entirely clear. He bargained with Roberto and bargained with his enemies; he was recognized as a vassalage by the prince of Benevento, and took the Benevento community as protection against him, starting the dominion of the Holy See over Benevento. Having taken a bite with Guiscardo, they collided even more.