Answer:
Chivalry was an important mode of proving your honor in the Middle Ages. It was also involved in the courting and winning of women.
In "Romeo and Juliet," the duels between Romeo and Tybalt and Tybalt and Mercutio are examples of the code of chivalry. After Tybalt calls Romeo a "villain," Mercutio defends Romeo's honor and his family's by duelling him.