Normans were founders of the English monarchy. They came from descendants of Vikings who lived in France. After Duke William invaded England he introduced Norman style feudalism. On the basis of relationships between lords and vassals, both the Capetains and the Normans managed to set up a feudal system that organized England and provided a reasonably good goverment.
Duke William (William the Conqueror) was the leader of the Normans. Normans were able to be succesful by building a centralized goverment, gaining title to all land in Normady, and strictly limiting the right of vassals to grant land to subvassals. All power was sustained by the dukes.
Internal Challenges: Capetains and Normans faced internal challenges from vassals seeking to pursue independent policies and enlarge their powers at the expense of the monarchs. External Challenges: Most Capetians and vassals often battled eachother, since the Normans periodically sought to expand their possession of France.