The prefixed word "court" comes from the latin "courtis" and refers to the place where the nobles show their loyalty to their Lords.
The term "courtly love" was born in the medieval age in the french literature and indicates the relationship the knight serves his courtly lady with the same obedience which he owes to his liege Lord. She is in complete control of the love relationship, while he owes her obedience and submission (a literary convention that did not correspond to actual practice!) The knight's love for the lady inspires him to do great deeds, in order to be worthy of her love or to win her favor. The act of loving is in itself ennobling and refining, the means to the fullest expression of what was potentially fine and elevated in human nature.