The Disputation of Barcelona (July 20-24 1263) was held at the royal palace of King James I of Aragon in the presence of the King, his court, and many prominent ecclesiastical dignitaries and knights, between Dominican Friar Pablo Christiani, a convert from Judaism to Christianity, and Rabbi Nachmanides (whose full name, Rabbi Moshe ben Nahman Gerondi, is often abbreviated as Ramban).
The disputation was organized by Raymond de Penyafort, the superior of Christiani and the confessor of King James. Christiani had been preaching to Jews of Provence. Relying upon the reserve his adversary would be forced to maintain through fear of wounding the feelings of the Christian dignitaries, Christiani assured the King that he could prove the truth of Christianity from the Talmud and other rabbinical writings. Nahmanides complied with the order of the King, but stipulated that complete freedom of speech should be granted.