[citation needed] The largest component, the Aquitainian, was led by Duke William VIII of Aquitaine (known as Guy-Geoffrey), whom one historian calls the "Christian generalissimo".

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.

[11] 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 eight thousand in those times.

[12][13] 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.

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.

[4] 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.

[15] 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.