Leonato, the Governor of Messina, Innogen, his wife, Hero, his daughter, and Beatrice, his niece, sit in front of Leonato's orchard. A messenger comes onstage to tell them that Don Pedro of Arragon is coming to Messina. They are all very excited, for they have not seen Don Pedro and his soldiers in a long time. The messenger tells him that only a few men have died in battle, but none of importance. He says that the young Claudio of Florence is the new hero of the battle. Beatrice asks about Signor Benedick of Padua with cynicism and harsh wit. The messenger proclaims that Benedick is doing well and is doting upon a new companion named Claudio. Beatrice speaks out against him, illustrating his friendship as a disease. Leonato explains to the messenger about the relationship between Beatrice and Benedick:
"You must not, sir, mistake my niece. There is a kind of merry war betwixt Signior Benedick and her: they never meet but there's a skirmish of wit between them."Act 1, Scene 1, lines 62-65
Don Pedro, Claudio, Benedick, Balthazar, and John the Bastard enter Antonio's orchard. They have arrived from battle and are welcomed warmly by Leonato. He and Don Pedro are old friends and embrace one another's company. Don Pedro recognizes Hero as his beautiful daughter, to which Benedick immediately responds with sarcasm. He begins a marathon of jokes and cynicism about the identity of Hero's parentage. Everyone listens to Beatrice and Benedick as they begin a witty exchange of insults. Beatrice swears to be single: "I had rather hear my dog bark at a crow than a man swear he loves me" Act 1, Scene 1, line 188. Don Pedro and his men decide to stay in Messina for at least a month.
Everyone exits the stage except Claudio and Benedick. Claudio is love-struck by Hero's beauty and asks Benedick his opinion of her. Benedick, a sworn bachelor, is shocked at Claudio's words and tells him that he does not think Hero is that beautiful. Claudio values his opinion, but also wants to marry Hero. Benedick tells him that he is crazy to think such things. He also mentions that Hero's cousin, Beatrice, is beautiful but has too strong a fury for any man in marriage. Don Pedro returns to the stage to get Claudio and Benedick to come inside to eat with the rest of the family. Benedick tells him that Claudio is in love with Hero and wants to marry her. Don Pedro is thrilled for the two. Benedick, however, feels differently about love.
"That a woman conceived me, I thank her; that she brought me up, I likewise give her most humble thanks: but that I will have a recheat winded in my forehead, or hang my bugle in an invisible baldrick, all women shall pardon me. Because I will not do them the wrong to mistrust any, I will do myself the right to trust none; and the fine is, - for the which I may go the finger, I will live a bachelor." Act 1, Scene 1, lines 247-256
Don Pedro tells Benedick that he plans to see him in love one day. Benedick responds by telling him that he will never be in love, no matter the circumstances. Benedick leaves and Don Pedro tells Claudio that he will help him win Hero's heart. Later in the same evening at a party in Messina, he will dress in a costume and assume Claudio's identity. He will woo Hero and ask for her hand from her father for Claudio.
