History professor Antonio Santosuosso puts forth an opinion on Charles, Tours, and the subsequent campaigns against Rahman's son in 736–737, presenting that these later defeats of invading Muslim armies were at least as important as Tours in their defense of Western Christendom and the preservation of Western monasticism, the monasteries of which were the centers of learning which ultimately led Europe out of her Middle Ages. He also makes an argument, after studying the Arab histories of the period, that these were clearly armies of invasion, sent by the Caliph not just to avenge Tours, but to begin the end of Christian Europe and bring it into the Caliphate.