Bellini was persuaded to write the opera for the 1830 Carnival season at the Teatro La Fenice in Venice, with only a month and a half available for composition.

He accepted both offers, but the La Fenice impresario, Alessandro Lanari, included a proviso that if he were to be unable to fulfill the Venice contract, then it would be transferred to Bellini.

By mid-December Bellini was in Venice where he heard the same singers who were to perform in Pirata: they were Giuditta Grisi, the tenor Lorenzo Bonfigli, and Giulio Pellegrini.

[3] The tentative contract deadline was extended until 20 January, but by that date Romani was in Venice, having already re-worked much of his earlier libretto which he had written for Nicola Vaccai's 1825 opera, Giulietta e Romeo, the source for which was the play of the same name by Luigi Scevola in 1818.

Eventually, revisions to Romani's libretto were agreed to, a new title was given to the work, and Bellini reviewed his score of Zaira to see how some of the music could be set to the new text, but composing the part of Romeo for Grisi.

Weinstock describes the premiere as "an unclouded and immediate success"[4] but it was only able to be performed eight times before the La Fenice season closed on 21 March.

[5] By this time, Bellini knew that he had achieved fame: writing on 28 March, he stated that: "My style is now heard in the most important theatres in the world...and with the greatest enthusiasm.

Later that year, Bellini prepared a version of Capuleti for La Scala which was given on 26 December, lowering Giulietta's part for the mezzo-soprano Amalia Schütz Oldosi.

The opera was first staged in the UK on 20 July 1833 and in the US on 4 April 1837 at the St Charles Theatre in New Orleans; later, first US performances were given in Boston on 13 May 1847 and in New York on 28 January 1848.

[9] The audience celebrated her performances enthusiastically and the critics compared Vestvali to Maria Malibran, Wilhelmine Schröder-Devrient and Rachel Félix.

[10] The opera was unheard in the 20th century until a concert performance was recorded for an RAI radio broadcast in 1957 with Antonietta Pastori as Giulietta, Fiorenza Cossotto as Romeo, and Lorin Maazel leading the music forces.

[12] The AOS presented the opera in concert again at Carnegie Hall in 1964 with Mary Costa as Giulietta and Simionato reprising the role of Romeo; a performance which was also recorded.

[12][13] La Scala staged the opera in 1967 using new designs by Emanuele Luzzati and musical forces led by Claudio Abbado.

[14] Aragall had sung this reworked version earlier under Abbado's baton at the Teatro Comunale di Bologna and the Holland Festival in 1966 with Margherita Rinaldi as Giulietta.

[12] The La Scala production toured to Expo 67 in Montreal, and its cast included Renata Scotto as Giulietta, Luciano Pavarotti as Tybalt, Agostino Ferrin as Capulet, and Alfredo Giacomotti as Lawrence.

[12] That same year the Vienna State Opera presented the work for the first time with Sona Ghazarian as Giulietta and Agnes Baltsa as Romeo.

In this version of the story the Capuleti and Montecchi are rival political factions (Guelph and Ghibelline respectively) rather than Shakespeare's "two households, both alike in dignity".

The doctor, Lorenzo, objects that Giulietta is ill with a fever, but Capellio brushes his warning aside and declares the wedding will take place immediately.

Duetto: Romeo: Sì, fuggire: a noi non resta / "Yes, flee, for us there is no other escape"; he demands: "What power is greater for you than love?

Romeo enters in disguise and tells Lorenzo, who immediately recognises him, that he is awaiting the support of his soldiers, one thousand of whom are assembled dressed as Ghibelines and who are intent on preventing the wedding.

Scene 2: The grounds of the palace An orchestral introduction precedes Romeo's entrance and introduces what Weinstock describes as "his bitter recitative", Deserto è il loco / "This place is abandoned", in which he laments Lorenzo's apparent forgetfulness in failing to meet him as planned.

The Capuleti and Montecchi rush in to discover the dead lovers, with Capellio demanding who is responsible: "You, ruthless man", they all proclaim.

"[23] Specifically, in regard to I Capuleti, she continues: Bellini lost no time in rescuing much of [Zaira's] material, reusing no fewer than eight numbers in his next opera.

But if we can take Bellini at his word, the extensive self-borrowing involved in recasting Zaira as I Capuleti was no lazy response to a looming deadline: although he was indeed forced to compose faster than he liked, he remarked repeatedly on how hard he was working, on one occasion complaining that the act 1 finale of Capuleti—one of the numbers copied almost literally from Zaira had nearly "driven him crazy."

The sheer volume of common material in these two operas ensures that dramatic resemblance between the recycled melodies in I Capuleti and their original incarnations in Zaira will be the exception rather than the rule.

[24]Smart then provides one specific example whereby word metering (the number of syllables for each line, traditionally written in a specific meter by the poet—the librettist—of from five to eight or more to each line of verse) is changed to work in the new context:[25] What are we to make of Bellini's decision to bring back the cabaletta for the prima donna soprano in Zaira, a number whose prevailing sentiment is giddy anticipation of an imminent wedding, as Romeo's lamenting slow movement in the last act of I Capuleti, sung over Juliet's inanimate body?

And as if to emphasize the violence of the transformation, the poetic texts are in different verse meters—Zaira's cabaletta in settenari,[26] Romeo's in the less common quinari[27] The means by which Bellini and Romani stretched Romeo's quinari lines to fit a melody originally conceived for settenari is ingenious, achieved simply by inserting word repetitions between the second and third syllables of each line.