Pope Alexander II first preached the Reconquista in 1063 as a "Christian emergency." It was also preached in Burgundy, probably with the permission or participation of Hugh of Cluny, where the abbot's brother, Thomas de Chalon, led the army. Certainly zeal for the crusade spread elsewhere in France, for Amatus of Montecassino notes that the "grand chivalry of the French and Burgundians and other peoples" was present at the siege. Thus, a large army was present at the siege when it began in 1064 primarily of Frenchmen and Burgundians, along with a papal contingent, made up mostly of Italians, as well as a local Spanish army made up of Catalans and Aragonese. Later, these Catalan and Aragonese soldiers would be disgusted by the crimes committed by those Normans after the capture of the city. The leader of the papal contingent was a Norman by the name of William of Montreuil. The leader of the Spaniards was Sancho Ramírez, King of Aragón and Navarre, whose realm was greatly threatened by the Moors to the south. The largest component, the Aquitainian, was led by Duke William VIII of Aquitaine, whom one historian calls the "Christian generalissimo". Though the makeup of this grand army has been subject to much dispute, that it contained a large force of Frankish knights is generally agreed upon. The duke of Aquitaine led the army through the Pyrenees at Somport. He joined the Catalan army at Girona early in 1064. The entire army then marched past Graus, which had resisted assault twice before, and moved against Barbastro, then part of the taifa of Lleida ruled by Al-Muzaffar. The city was besieged for forty days until it surrendered according to both Muslim and Christian sources. Aside from William of Montreuil and Guy-Geoffrey, a 1078 story about the Normans placed Robert Crispin as the leader of the campaign.
Consequences
Terms were given by the Christians to spare the lives of the Muslims and respect their properties, but the pact was quickly broken. Another source tells that the garrison offered to surrender their property and property of their families in exchange for letting them leave the town, and so it was agreed with the besiegers. However, the Crusaders didn't honour the treaty and killed the soldiers as they came out. Crusade soldiers plundered and sacked the city without mercy. It is said fifty thousand Muslims were killed or captured and the victors divided an enormous amount of booty. The contemporary Muslim chronicles suggest the invading forces might have slain the adult males and enslaved women and children; the numbers however are greatly exaggerated: Barbastro would hardly reach a population of two thousand in those times. The Andalusi Muslim jurist Ibn 'Abd al-Barr, among the witnesses of the fall of Barbastro, described the aftermath as follows:
"What can be your opinion, Oh Muslims, when you see masajid and oratories, that once were witness to the recitation of the Qur’ān and the sweetness of the call to prayer; immersed in širk and slander, loaded with bells and crosses, in the place of the followers of ar-Raḥmān: aʼimmah and pious men, vergers and muʾaḏḏinūn...are dragged away by the kuffār like animals for sacrifice, they are brought to the butcher; they prostrate themselves humbly in the masajid which are then burnt and reduced to ashes while the kuffār laugh and insult us, and our Dīn wails and weeps."
The plight of women seems to have been particularly difficult as a consequence of the siege and victory of the crusaders. Many died during the siege of thirst-related diseases and were subjected to degrading treatment after victory, converting them into servants and slaves, or sometimes even exposing them to the torture of their husbands. The crusaders made off with a huge booty. The Kitab al-Rawd al-Mitar records the capture of a good many Saracen girls and Saracen treasures. Armengol III of Urgel, the brother-in-law of King Sancho Ramírez, was entrusted with the government of the city. On 17 April 1065, after roughly ten months of occupation, the Moors easily retook the city. Thibaut, the Burgundian leader, died, possibly of wounds received on campaign, while returning to France after the loss of the city in 1065.
Historiography
Historian Reinhart Dozy first began a study of the War in the mid-nineteenth century based on the scarce primary sources, mainly Amatus and Ibn Hayyan. Dozy first suggested the participation of a papal element based on Ibn Hayyan's reference to the "cavalry of Rome." Subsequent historiography has stressed the Cluniac element in the War, primarily the result of Ferdinand I of León's recent attempts to introduce the Cluniac reform to Spain and inspired by the death of Ramiro I of Aragon following the failed Siege of Graus. This interpretation has been criticized in more recent decades, especially the papal connection and Italian involvement. It has been suggested that Alexander was preoccupied with the Antipope Cadalus at the time and did not preach a plenary indulgence for warriors of the Reconquista until the 1073 campaign of Ebles II of Roucy. It has also been theorized that it was not William of Montreuil, but Guy Geoffrey, who was the "Roman" leader implied by Ibn Hayyan.
