Other Educators have noted in answer to this question that in act 2, scene 4 of Shakespeare's Romeo and Juliet, Benvolio tells Mercutio that Tybalt sent a letter to the Montague household, which Mercutio believes challenges Romeo to a duel.
BENVOLIO. Tybalt, the kinsman to old Capulet,
Hath sent a letter to his father's house.
MERCUTIO. A challenge, on my life. (2.4.6-8)
Such a letter was called a cartel, which was the formal, written means of initiating a duel in Europe during the Renaissance.
Dueling was common in Elizabethan England, but by the 1700s dueling was made illegal throughout most of Europe. No mention is made of whether or not dueling was against the law in Verona at the time Romeo and Juliet is set. Nevertheless, the Prince issued a very stern warning about fighting to the Capulets and Montagues.
PRINCE. ...If ever you disturb our streets again,
Your lives shall pay the forfeit of the peace. (1.1.92-93)
Perhaps a private duel wasn't considered disturbing the peace if it didn't take place in...
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