Prince: Romeo slew him, he slew Mercutio; Who now the price of his dear blood doth owe?
 Montague: Not Romeo, prince, he was Mercutio’s friend, 155 His fault concludes but what the law should end, The life of Tybalt.
Prince: And for that offence Immediately we do exile him hence: I have an interest in your hate’s proceeding, 160 My blood for your rude brawls doth lie a-bleeding; But I’ll amerce you with so strong a fine That you shall all repent the loss of mine.

In this excerpt, the prince is an antagonist because he?