When we first see Romeo, he’s acting lovesick, and he explains to Benvolio that he’s in love with a woman who doesn’t return his “favor.” Romeo doesn’t identify the woman here, but somewhere between this scene and the next Benvolio learns her name, since in the later scene he points out that she’s on the guest list for the Capulet ball: “At this same ancient feast of Capulet’s / Sups the fair Rosaline whom thou so loves” (I.ii.83–84). From this reference, it becomes clear that Romeo is in love with a woman named Rosaline, and that she, like Juliet, is a Capulet. Benvolio then suggests that Romeo should try to get over Rosaline by going to the ball and looking upon “all the admired beauties of Verona” (I.ii.85). Benvolio insists: “Compare her face with some that I shall show, / And I will make thee think thy swan a crow” (I.ii.87-88). Romeo follows Benvolio’s advice to the letter. And although Rosaline never appears onstage, she nevertheless plays an important role, since her rejection of Romeo ultimately leads him to his first, fateful encounter with Juliet.
Friar Laurence gives us an additional perspective on Rosaline in Act 2, scene 3, when Romeo explains to him that he’s switched his love from Juliet to Rosaline. Whereas Romeo had told Benvolio that Rosaline had rejected him because she’d sworn to remain “chaste” forever, Friar Laurence suggests that Rosaline didn’t believe Romeo’s love to be authentic, saying “Oh, she knew well, / Thy love did read by rote that could not spell.” In other words, she knew Romeo was only acting the way he thought somebody in love would act, and not because he actually felt that way. Friar Laurence’s comment undercuts the idealized picture of Rosaline that Romeo painted for Benvolio, creating the impression (in a very brief moment) that Rosaline might be an actual person with realistic feelings and attitudes, rather than just the name of someone Romeo is infatuated with.