How does Valentine becomes the leader of bandits in Two Gentlemen of Verona?

At the end of Two Gentlemen of Verona, Silvia decides to follow Valentine and passes through the same wood as Valentine and is seized by bandit. Proteus saves Silvia from the bandits and once again begs her to marry him. Valentine, now leader of the bandits, appears. Proteus is thus caught courting Silvia. He is at once shamed and remorseful at having deceived his best friend. Gentle and noble Valentine forgives him and impulsively offers him Silvia.