The Saxon chiefs beheld Charlemagne for the first time in the majesty of peaceful surroundings. Heroes of the sword and dignitaries of the Church were gathered around his throne. Many of these chiefs willingly acknowledged such a master. It happened also that a Moorish Embassy from Spain was in Paderborn at this time. The Saxons beheld the newcomers with astonishment, so different was their splendid attire from that of the northern peoples. The Moorish leaders had come to seek the help of Charlemagne against Abderrahman, Caliph of Cordova, and promised to transfer their allegiance to him in case he freed them from his power. Charlemagne was glad of the opportunity to interpose in Spanish affairs. He promised to help the petitioners, and in the meantime decided to demand a district in northern Spain for himself as a defence, in case of emergency, against the Moors of the southern part. The Saxons for the first time realized the wide extent of his authority and fame. How could they longer withstand him, they asked themselves. Ozanam says: “Many of them swore allegiance and promised to surrender their country and their freedom if they violated their word. Many renounced idol worship and were baptized. A multitude of men, women, and children went down to the river in white garments, accompanied by chanting priests, and came back Christians; at their head the priests and monks, who had thus laid the foundations of the Christian Saxon Church. The world rejoiced at the conversion.” No one was more delighted than Charlemagne. It heightened his hope and enthusiasm when he set out upon the Spanish expedition the following year. He crossed the Pyrenees, overcame Pampeluna and Barcelona, and made Navarre, Aragon, and Catalonia subject to his authority. Saragossa was next invested, and after a short resistance its people submitted to him and gave hostages and tribute. Thereupon he made northeastern Spain, as far as the Ebro, the limit of the Frankish kingdom in Spain, and established a barrier against the Moors, intending thereby to discourage pagan invasions and prevent the disturbance of the Christian world, as his grandfather had done before him.