Reconquest and Crusade in Medieval Spain - Joseph F. O'Callaghan - Google Books

https://books.google.de/books?id=4gVIt5u0U5wC&pg=PA94#v=onepage

Drawing from both Christian and Islamic sources, Reconquest and Crusade in Medieval Spain demonstrates that the clash of arms between Christians and Muslims in the Iberian peninsula that began in the early eighth century was transformed into a crusade by…