But once he is at the Capulet’s party, he forgets Rosaline very quickly because he sees the most beautiful girl he has ever seen: “Did my heart love till now? Forswear it sight, for I ne’er saw true beauty till this night”. But it is Juliet Capulet. The fact that he falls in love so quickly with Juliet when we thought he deeply loved Rosaline show us that he is fickle. The sonnet he shares with Juliet shows us once more that he is very romantic: “O then dear saint, let lips do what hands do. They pray; grant thou, lest faith turn to despair”. Romeo is feeling very happy there because he is with the girls he likes. But the premonition he had that things were going to go wrong became true: Juliet is a Capulet, daughter of his family’s enemy. Romeo is devastated: “Oh dear account, my life is my foe’s debt” Since then, we can realise that Romeo’s love for Juliet is sincere. This is showed once again when Romeo enters the Capulet’s orchard to go to Juliet’s balcony because he says: “With love’s light wings […] thy kinsmen are not to stop me”; Romeo is pretty brave because he could be killed if a Capulet sees him, and a little foolhardy as well I guess because he doesn’t really realize that, he just thinks about being with his love. I think this love is stronger than the love Romeo felt for Rosaline because Juliet really loves him back. And we are sure that the feelings Romeo has for Juliet are sincere because he expresses them in a soliloquy: “He jests at scars […] cast it off”. During this entire scene, Romeo declares his love to the young girl: “Ah Juliet […] by this dear encounter”; and even promises her he will arrange a marriage “Save what […] by holy marriage”.
As the two lovers have been married (in Act II scene 6), Tybalt has become Romeo’s cousin. The young Montague is in the streets of Verona with Mercutio and Benvolio when Juliet’s cousin challenges Romeo to fight against him. Romeo is not a coward but still refuses to fight because Tybalt is his cousin and he doesn’t want to hurt his wife: “Tybalt […] the appertaining rage”. So Romeo steps between Mercutio and Tybalt to stop the fight: “Hold Tybalt. Good Mercutio”. He isn’t aggressive at all during the fight even though he is against it, but his attitude greatly changes after Mercutio’s death: Romeo feels guilty because he didn’t fight Tybalt, “My very friend, hath got this mortal hurt in my behalf”, he realizes his love for Juliet has made him effeminate, “Thy beauty hath made me effeminate”, he also becomes very violent and kills Tybalt for revenge of Mercutio: “Now Tybalt […] go with him”. Though he feels aware of the implications of his foolish actions afterwards, “O I am fortune’s fool”. But it is already too late.
Too late because all the citizens have arrived, followed by the Prince. As a conclusion, Romeo is banished: he has to leave the city to go to Mantua. The young Montague is really upset because he won’t see Juliet anymore, since she is staying in Verona: “ ‘Tis torture […] that word banished?”. He even thinks that death would have been preferable to banishment: “Ha, banishment? Be merciful, say ‘death’’; for exile hath more terror in his look, much more than banishment’’. He even says he could kill himself, only because he is a Montague: “he offers to stab himself”. At the end of this scene, Romeo is feeling a little bit better because Friar Lawrence promises he’ll try to solve things out, and makes Romeo see the positive side of the situation: Juliet is still alive and Tybalt could have killed him. After spending the whole night with Juliet, Romeo has to leave for Mantua. Even though he would prefer to stay with his love, he changes his mind about death being worse than banishment because Juliet tells him to go and the Friar has given him positive thoughts to take with him to Mantua.
So we have seen the evolution of the character of Romeo throughout the first three acts of the play and we can conclude that at the beginning Romeo is a young fickle and immature gentleman, and he turns out to become a married man banished from Verona, but who gains in maturity and has a crime on his conscience.
