What is Tybalt's role in Shakespeare's Romeo and Juliet?

Tybalt represents the ongoing feud between the houses of Capulet and Montague. He is indirectly responsible for the tragic deaths of Romeo and Juliet. He tries to provoke a quarrel with Romeo because he feels outraged at Romeo's party-crashing in Act I, Scene 5. When Romeo refuses to fight because he is now married to Juliet and wants harmony with the entire Capulet family, Romeo's friend Mercutio challenges Tybalt and is mortally wounded. Mercutio is an easy-going man as a rule, but he believes in defending Romeo's honor, and the honor of the Montague family, including his own honor, is compromised by Romeo's refusal to fight. So this endless feud between the two houses is still very much alive. Romeo is so angered by Tybalt's slaying of his good friend Mercutio that he challenges Tybalt to a sword fight and kills him. This leads to Romeo being banished from Verona by the Prince. The well-meaning Friar Laurence is also indirectly responsible for the tragic outcome of the story. His letter does not reach Romeo, who returns to Verona from Mantua thinking Juliet is dead. Romeo commits suicide, and then Juliet kills herself when she wakes up and finds her husband dead. The hot-tempered and impetuous Tybalt triggered the deaths of the "star-crossed lovers" with his belligerence. Without Tybalt, it is possible that Romeo and Juliet would have brought peace between their families through their love and marriage.