Answer:
Franks = Germanic-speaking people who invaded the Western Roman Empire in the 5th century
Secular = denoting attitudes, activities, or other things that have no religious or spiritual basis (basically unreligious)
Charlemagne = Former King of the Franks
Feudalism = Feudalism, also known as the feudal system, was a combination of the legal, economic, military, and cultural customs
Lord = a person or deity who has authority, control, or power over others, acting like a master, a chief, or a ruler
Fief = an estate of land, especially one held on condition of feudal service
Vassal = a holder of land by feudal tenure on conditions of homage and allegiance
Serf = an agricultural laborer bound under the feudal system to work on his lord's estate
Manor = a large country house with lands
Chivalry = the medieval knightly system with its religious, moral, and social code
Hope this helps :)