Feudal System. The economic expression of the lord-vassal-peasant social stratification was in grants of land coming from the most powerful warrior to his loyal military supporters. As a result of one military enterprise alone in 732, the Frankish leader Charles Martel usurped from the medieval church, the only vulnerable source at the time, a large portion of its landholdings in Frankish territory. After his defensive defeat of the Muslims who were attacking Frankish lands from the south, he needed land to give to his followers as an adequate source of revenue to allow them to continue to equip themselves as knights with the costly horses and armor required. Martel's strategy of compensating his loyal followers led to what would come to be identified as the medieval feudal system with its economic ingredient, land grants, its military service based on...