Duke William and the Crusaders enter Calatayud, 14th century manuscript
The Fall of Cordoba by James Richmond said:
When news arrived at Coimbra of the fall of Calatayud, the war council was greatly shaken and advised the Governor to confront the Franks instead of Braganza. "Let the Franks have the rotten acorns while we pluck up the ripe fruits," Abd al-Malik responded, fully dismissive of the threat. The swift conquest of the north thereafter proved him right, for the time being.
On the Feast of the Three King's (6th of January), 1079, the citadel of Calatayud finally surrendered to the crusader army, and William of Toulouse made a name for himself throughout Iberia by his kind treatment of the defeated after entering the city. He even forgave the wily Sheik Mohammad, who died soon after of battle wounds, promising to take care of the former ruler's family and household.
The war, however, was not over and it even expanded. Count Adhémar, though he had promised to leave Spain, instead entered the province of Tarragona, the last holding of the Emirate of Zaragoza, in order to gain at least something out of this crusade. He further made an ally of Sheik of Albarracin, former vassal of Zaragoza, and together the two defeated the forces of the Emir (at the time, the four year old son of the late Yusuf) on the 24th of February. They laid siege to the city, jubilant over the prospect of dividing the loot between the two hosts, but Duke William intervened in these plans.
Incensed at news of the greed of Adhémar and his unholy alliance, William marched in matter of a couple of weeks to Tarragona and took command of the siege. Count Adhémar raged, but both royal and papal envoys present supported William as leader of the armies and only he, unless otherwise commanded by the King of France or the Holy Father, had sole right to take and dispose of captured cities, lands, and booty. As it happened the city fell just four days after the arrival of William and his armies (20th of March). The Duke's first act was to bury the body of his brother Raymond (who had died of his wounds from earlier battle and fever a week before) within the walls of the former mosque. The citizens were again surprised to receive the same chivalrous treatment that Calatayud had gotten. One chronicler put it this way; "Though they [the people of the cities] were apostates after the order of Mohamet, the Duke saw no reason to chastise them, as they were as innocent babes, not knowing the true faith. Thus, he bade his knights to let them alone and do only good, so that the land would know peace."
The infamous Emperor Henry IV
Yet, while Spain north of the Ebro settled under the peaceful, but strong hand of the Duke of Provence, the rest of world was still on the march. After crushing Christian armies at Coimbra in January, Abd al-Malik swept northward in Galicia. King Enrique I of Leon finally got word of these tidings and attained a truce with the Fatimid Sultan, al-Mustansir, which allowed him to keep Alexandria. The Pope was displeased, as it had seemed that the total conquest of Egypt might have been at hand. The man who offered to continue the conquest, however, was the most unlikely in all Christendom, Henry IV, Holy Roman Emperor. In order to "atone" for his sins and perhaps gain Papal approval at last for his meddling in Italian affairs, Henry set sail for Egypt in July. Meanwhile to the south, Robert Guiscard continued an aggressive series of wars for control of Sicily, defeating the various Muslim factions of the island at will in his own, much less gentlemanly, crusade.
William of Toulouse was not inactive in this time and the last quarter of the year saw his plans bare fruit. The success of Cordoba could not be ignored, but William was in no condition personally intervene. He was made privy by the advisers or the late Sheik Mohammed to the rivalries of the various Muslims city-states, especially the hatred that the Emir of Toledo bore for Cordoba and its proud Governor. The Duke spurred the Emir through secret correspondence to rise up against the Governor while Cordoba was so engaged in the north. The Emir took the bait and launched his surprise attack in October, defeating a Cordoba host at Sevilla and then Alcacer do Sal five days later.
Capping it all, after gaining the blessing of the King and the Pope, William proclaimed Zaragoza a "Duchy of the Kingdom of the Franks," on the 9th of December. The power that came with this upset the balance in northern, Christian Spain firmly in favor of William and his leige, to the total displeasure of Count Ramon I Berenguer and King Sancho of Navarra.