(in Latin Jannonus), Pietro, a celebrated Neapolitan writer and historian, was born at Ischitella, a small town in the province of Capitanata. Having acquired the elements of a liberal education under the paternal roof, he was sent by his father, at the age of eighteen, to Naples, there to complete his studies, and particularly to study jurisprudence. Being placed under the immediate tuition of the learned Dominico Aulilio, he applied himself with great ardour to the study of jurisprudence on philosophical principles, and soon gave proofs of his capacity for investigating and illustrating the sources of that science by several learned dissertations De Originibus Juris. His inquiries, however, having disclosed to him much respecting the origin and mutations of laws, and the vicissitudes of nations, which had escaped the penetration of ordinary jurists, he conceived the design, with the approbation of Argento, of writing a civil history of the kingdom of Naples, comprehending an account of the origin and progress of its laws and government, and an exposition of the causes which led to the gradual abolition of ancient customs and institutions. But this work, interrupted from time to time by the affairs of the bar, was not completed until after the lapse of twenty years, and only appeared in 1723, under the title of Istoria Civile del Regno di Napoli, in four volumes 4to. Giannone took as his guide Angelo di Costanzo, whose history of Naples, which was then accounted the best, he almost entirely transfused into his work; but his distinguishing merit consists in the valuable expositions he has given relative to the ecclesiastical and civil constitution, and to the laws and customs of the kingdom. Although the style is neither correct nor elegant, the philosophical spirit, the erudition, and the profound research, which this history exhibits, secured it a high reputation. The freedom with which he treated ecclesiastics generally, and the bold- ness with which he discussed several topics relating to the origin of the papal power, raised a storm against him, which neither the authority of the viceroy, Cardinal Altamira, nor the credit of the municipality of Naples, of which he had been elected advocate, could allay, or even mitigate. "I know not, indeed," said Argento, when speaking to him on this subject, "whether I should congratulate you or console with you; for I very much fear lest the crown of laurel which now encircles your brows should become a crown of thorns." Having been several times insulted by the populace, and at length excommunicated by the archiepiscopal court, Giannone, seeing his work placed in the index expurgatorius, left Naples on the 29th of April 1723, and went to seek an asylum at Vienna. The Emperor Charles VI. regarded him at first with an unfavourable eye; but the protection of such men as Prince Eugene, the Chancellor Zinzendorf, the celebrated Count de Bonneval, and the Chevalier Garelli, first physician to the emperor, procured him a pension of a hundred florins on the secretariatship of Sicily. During his stay at Vienna, where he enjoyed the favour of the great and of men of letters, he laboured at a work entitled Il Triregno, ossia del regno del Cielo, della Terra, e del Papa, which occupied him nearly twelve years, and to which he only put the last touches at Geneva. This work, in which man is successively represented in the state of nature, under the law of grace, and under the temporal dominion of the popes, comprehends ten epochs, the first three of which extend to the ninth century; but the remainder has not been completed. Don Carlos having ascended the throne of Naples and of Sicily in 1734, Giannone lost his pension and all his hopes. Being constrained to quit Vienna, he retired to Venice, where he was received with every mark of distinction. He refused the appointment of counsellor of the republic, and the chair of Roman law in the university of Padua, ingenuously confessing that he was not in a condition to explain the laws in the Latin language, according to the usage of the schools. But the repose which he hoped to enjoy at Venice was not of long duration. Denounced as unfavourable to the pretensions of the republic over the Adriatic, he endeavoured to avert the storm by publishing a Lettera intorno al dominio del mare Adriatico ed ai trattati seguiti in Venezia tra Papa Alessandro III. e l'Imperador Federigo Barbarossa; but as the state inquisitors had taken umbrage at the prolonged visits paid by him to the ambassadors of France and Spain, his removal was decided on, and, in the night of the 23rd September 1735, shirri seized and conducted him in a small boat to the frontiers of the territory of Ferrara. The apprehension of still greater misfortunes now induced him to change his name to that of Antonio Rinaldo, under which he sojourned at Modena, Milan, and Turin, and arrived with his son at Geneva on the 5th of December. His reputation, which had preceded him in different cities, procured him in the last-mentioned place the most satisfactory reception on the part of Dr Turretin, the minister Vernet, and the bookseller Bousquet, who furnished him with the means of living at his ease. In 1736 he was preparing to print a volume of supplement to his history, when, having been conducted by a perfidious friend to pass Easter in a catholic village belonging to the king of Sardinia, he was arrested by order of that sovereign, and his manuscripts were seized and sent to Rome. He was himself conducted to the castle of Miolan, and thence to the fort of Ceva. Afterwards, his Sardinian majesty ordered him to be transferred to the citadel of Turin, where he passed twelve consecutive years in trouble and agitation. It was in this fortress that, giving ear to the persuasions of Father Prever of the Oratory, Giannone retracted, on the 4th April 1738, the maxims in his history which had been condemned. But this submission did not procure him his liberty; for he died in prison on the 7th of March 1758, aged seventy-two years.

In 1760 his posthumous works were published at Lausanne, in one volume 4to, under the title of Opere Postume in difesa della sua Storia civile del regno di Napoli, con la di lui professione di fede. The History of Giannone was translated into French by Louis Bochat of Lausanne; and among the re-impressions of the work may be distinguished that which appeared with illustrations by the Abbé Cestari. It has been highly commended by Gibbon in his Extraits de mon Journal (Miscellaneous Works, vol. v., p. 413, 8vo ed.). "The candour, penetration, and freedom of this excellent lawyer," says he, "will ever ensure to this work the esteem of all wise men. But," he adds, "churchmen are not always of the number." In the number of the refutations which have appeared, it is only necessary to mention the Riflessioni morali e teologiche sopra l'Istoria civile del regno di Napoli, by Eusebio Filopatro (Father San-Felice, a Jesuit), in two volumes 4to, an extract of which may be seen in the Mémoires de Trevoux for January 1750. (Fabroni, Vite Italorum, vol. xiii. v. Petrus Jan-nonius—Bing. Univ.)