Act 3, scene 1 of Shakespeare's Romeo and Juliet brings to a head a conflict that emerges in the play's first scene. In act 1, scene 1, a brawl breaks out between servants of the Capulets and servants of the Montagues that quickly draws in Benvolio (a Montague kinsman) and Tybalt (a Capulet kinsman). The citizens of Verona have to work hard to restore the peace, and the Prince himself gets involved, telling the two families (the heads of which have arrived on the scene) that if such a thing ever happens again, the one responsible will receive a sentence of death.
Tensions remain high as the scenes pass. When Tybalt discovers that Romeo, Benvolio, and Mercutio are present at the Capulet masked party, he is furious and longs for a fight right then. Only Capulet himself, the family's patriarch, is able to hold him back.
In act 3, scene 1, the tensions break out into violence. Benvolio and Mercutio are walking along the street when Tybalt and his companions enter. Tempers are already beginning to flare when Romeo arrives. By this point, Romeo and Juliet are already married, and the last thing Romeo wants to do is fight with Tybalt. Mercutio, however, becomes violently angry and draws his sword on Tybalt. Romeo attempts to separate the two men, but Tybalt reaches past Romeo and kills Mercutio. Romeo then kills Tybalt. Their brawl, of course, does not go unnoticed by the citizens of Verona, and the Prince enters. On Benvolio's explanation and plea, he exiles Romeo instead of executing him but threatens that if Romeo is ever discovered in Verona again, he will die.