NUNCIO, or NUNTIUS APOSTOLICUS, a representative of the pope sent on diplomatic mission. The nuncios are of lower rank than the legati a lalere, but have practically superseded them as ambassadors of the papacy. Nuncios were permanently established at various courts and ecclesiastical centres during the 16th century. According to the decision of the congress of Vienna the diplomatic rank of a papal nuncio corresponds to that of an ambassador. The powers of a nuncio are limited by his instructions. If a cardinal, as rarely is the case, he uses the title pro-nuntius. The pro-nuntius at Vienna has practically the position of a legatus a latere.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)