Complex sentence: They even pushed farther than the Pyrenees towards France until, in 732 A.D. the Franks led by Charles Martel, defeated them at Tours, thus preventing the further expansion of Islam in Southern Europe.
Split into simpler sentences: They even pushed farther than the Pyrenees towards France. In 732 A.D. the Franks led by Charles Martel, defeated them at Tours, thus preventing the further expansion of Islam in Southern Europe.