Vassalage was originated by the Germans when the warriors would she loyalty by swearing an oath to their leader. The leader provided for them while they worked hard by fighting. Because the noblemen had so much land, help was needed, and so they used vassals who would protect the land while the leader would give them a portion of the land. The way that the cavalry fought began to change. The men now wore chain mail and used lances instead of spears. These warriors became known as knights. The lord would hire vassals, and give him land to live on and to support his family with, and the vassal would fight for the lord. The loyalty of a vassal to his lord was the key element in the system.