Social Classes
Kings played a great role in the daily life of people during the Middle Ages. The King was in charge of collecting taxes, making laws, punishments, and so on. Below is a photo of one of England's Anglo-Saxon Kings, Edward the Confessor.
The adjective noble means honorable, loyal, and worthy. This was exactly the role of a noble: to be loyal and honorable towards their king. "Paying homage" is just another way of saying paying respect towards, essentially what kings expected of his nobles. Below is an image of a noble.