In Much Ado About Nothing, the prince who helps bring Beatrice and Benedick together is Don Pedro.
Don Pedro is the Prince of Aragon and the leader of the soldiers who arrive in Messina. He recognizes that Beatrice and Benedick, despite their constant arguments and witty insults, are well matched. He therefore helps organize a deception designed to make each overhear that the other secretly loves them.
The plan works because both characters are proud and verbally combative. Benedick overhears Don Pedro, Claudio, and Leonato discussing Beatrice's supposed love for him, while Beatrice hears Hero and Ursula speak about Benedick's feelings. Their hostility gradually turns into genuine affection.
Don Pedro should not be confused with Don John, his resentful half-brother. Don John schemes to damage Claudio and Hero's relationship, whereas Don Pedro generally supports the play's romantic unions. The character's matchmaking is one of the comedy's central examples of “noting”—overhearing, gossip, and staged information.