In its initial stages, feudalism was important because it helped William I to earn the loyalty and specific services from noblemen who had served in his army. This system was established by William I because he was not popular and influential among the people of England.
William I partitioned the land into large plots and gave them to soldiers who had fought in battles with him. He wanted to earn the trust of people who were ready to die for him and would be faithful to him. The noblemen had to swear by the Bible to show devotion and loyalty to him. They had to collect taxes in their areas for William I, and they also had to provide soldiers when requested.