It was not until the turn of the twelfth century—not coincidentally, the dawn of the crusading era, when Islamic cities with scholarly communities like Toledo, Córdoba, Palermo, and Antioch came under Christian control, and Damascus, Alexandria, and Baghdad were suddenly more accessible than before—that the intellectual boundaries thrown up between the Arab and Christian blocs began to collapse, and scholarship both new and forgotten began flooding from the Arab world to the west.
