Benvolio, who began this bloody fray?

Prince
Benvolio, who began this bloody fray?
Benvolio
Tybalt, here slain, whom Romeo’s hand did slay—
Romeo, that spoke him fair, bid him bethink
How nice the quarrel was, and urged withal
Your high displeasure.

Let Romeo hence in haste,
Else, when he is found, that hour is his last.

All this utterèd
With gentle breath, calm look, knees humbly bowed
Could not take truce with the unruly spleen
Of Tybalt, deaf to peace, but that he tilts
With piercing steel at bold Mercutio’s breast,
Who, all as hot, turns deadly point to point
And, with a martial scorn, with one hand beats
Cold death aside and with the other sends
It back to Tybalt, whose dexterity
Retorts it. Romeo he cries aloud
“Hold, friends! Friends, part!” and swifter than his tongue
His agile arm beats down their fatal points,
And ’twixt them rushes; underneath whose arm
An envious thrust from Tybalt hit the life
Of stout Mercutio, and then Tybalt fled.
But by and by comes back to Romeo,
Who had but newly entertained revenge,
And to ’t they go like lightning, for ere I
Could draw to part them was stout Tybalt slain,
And, as he fell, did Romeo turn and fly.
This is the truth, or let Benvolio die.
Lady Capulet
He is a kinsman to the Montague.
Affection makes him false; he speaks not true.
Some twenty of them fought in this black strife,
And all those twenty could but kill one life.
I beg for justice, which thou, prince, must give.
Romeo slew Tybalt; Romeo must not live.
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.
His fault concludes but what the law should end,
The life of Tybalt.
Prince
And for that offense
Immediately we do exile him hence.
I have an interest in your hearts’ proceeding:
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.
I will be deaf to pleading and excuses.
Nor tears nor prayers shall purchase out abuses.
Therefore use none. Let Romeo hence in haste,
Else, when he is found, that hour is his last.
Bear hence this body and attend our will.
Mercy but murders, pardoning those that kill.
  They exit, the Capulet men bearing off Tybalt’s body.