Serfs were mostly peasant farmers who provided labor in their masters land. Peasants would pay the lord by working for them in exchange to use their lords land to generate their own food. Serfs did not have money. they were basically slaves. They would work at least three times a week. The serf was bound to work in a single manor. The status of serf was passed down to their children.
I think its because of power or it commands more of respect or it was for decoration for the helmet. i hope this helps you.
Explanation: You have more people to govern, which means you need rules and procedures to have a strong government to be able to control a populist and a balanced one so you don't lose support of your citizens. A doom government is one with no support.
