Outside the USA, Ponselle sang only at Covent Garden in London (for three seasons) and in Italy (in order, so she said, to honor a promise she had made to her mother that she would one day sing in Italy). In 1929, Ponselle made her European debut in London, at the Royal Opera House at Covent Garden. Up until that time, her career had been concentrated entirely in America. Ponselle sang two roles at Covent Garden in 1929: Norma and Gioconda. She had great success and was tumultuously acclaimed by the normally staid London audiences. She returned to London in 1930 in Norma, L'amore dei tre re, and La traviata (her first performances as Violetta). In her final London season in 1931, she sang in La forza del destino, Fedra (an opera by her coach and long-time friend, Romano Romani), and a reprise of La traviata. In 1933 Ponselle sang her only performances in Italy, as Giulia in La vestale, with the Maggio Musicale in Florence. As in London, the audiences were wildly enthusiastic. At the second performance, Ponselle had to encore the aria, "O nume tutelar". Her success was such that she considered an engagement at Milan's La Scala, but after witnessing a Florence audience's brutal treatment of a famous tenor, Giacomo Lauri-Volpi, who cracked on a high note, she decided not to press her luck further with the notoriously difficult Italian opera-going public. Other than her appearances in London and Florence, Ponselle never sang outside the United States. Ponselle continued in the 1930s to add roles to her repertoire at the Metropolitan Opera. In 1930 she sang her first New York appearances in 1931 as Violetta, a role she had sung with such success in London, received a more mixed reception from the New York critics, some of whom found her interpretation too forceful and dramatic. (W.J. Henderson complained of her "assaults" on the vocal line.) In 1931 she sang in another unsuccessful world premiere, Montemezzi's La notte di Zoraima, which sank without a trace. Like many other opera singers of that time, she made a brief trip to Hollywood and made screen tests for Metro-Goldwyn-Mayer and Paramount Pictures, but nothing came of them. In 1935, Ponselle sang her first Carmen at the Met. In spite of a great popular success with the role, for which she had prepared meticulously, Ponselle received a drubbing from most of the New York critics, especially Olin Downes in the New York Times, whose savagely caustic review hurt Ponselle deeply. The only roles Ponselle sang during her last two seasons at the Met were Santuzza and Carmen, roles that did not tax her upper register. Differences with the Met management regarding repertoire led her not to renew her contract with the company for the 1937/38 season. Her last operatic performance was as Carmen on April 22, 1937, in a Met tour performance in Cleveland.

Answer this question "What year did she begin to perform in London?" by extracting the answer from the text above.
In 1929, Ponselle made her European debut in London,