Giovanni Giacomo De Seingalt Casanova, an Italian adventurer, born in Venice, April 2, 1725, died in Austria about 1803. His father, who was of noble descent, was an adventurer and comedian, and married the daughter of a Venetian shoemaker. Giovanni was sent to Padua, and placed under the instruction of Gozzi; but having been implicated in a brawl between the students and the police, he was forced to leave Padua, and went to Venice. His adventures there are described in his memoirs, and reveal the frivolous character of the Venetian society of those days. Having become notorious for his profligacy, he was finally thrown into the dungeon of San Andrea, but effected his escape, and, after wandering over various towns of Italy, succeeded in finding at Morterano a prelate to whom he brought letters of introduction which his mother had obtained for him, and who recommended him to his friends at Naples. They in turn supplied him with letters to Cardinal Acquaviva in Rome, who brought him into personal contact with Pope Benedict XIV., and this circle of acquaintance laid the foundation for his subsequent career.

His devotion to the poetical Marchesa Gabrielli, his mental encounters with the literati, his conversational triumphs in the high social circles of Rome, were all brought to a sudden close by his connivance in an elopement which gave offence to the marchesa, who requested Cardinal Acquaviva to dismiss Casanova, whom he employed as secretary. The cardinal gave him a passport for Venice, and he eventually reached Constantinople, in company with the Venetian ambassador, into whose favor he had insinuated himself. He was received with great distinction by Cardinal Acquaviva's friend, the pasha of Caramania, alias count de Bon-neval, who introduced him to YusufAli, whoso wife fell in love with him, while his daughter Zelmi was offered to him in marriage. He left Constantinople surfeited with presents and money, which he lost in gambling soon after his arrival at Venice in 1745, where he accepted a humble musical employment in the orchestra of the theatre San Samuele, in order to save himself from starvation. Here he fell in with the rich Venetian senator Bragadio, but was soon again compelled to remove to other places in order to escape the hands of justice.

After figuring as a magician at Cesena, as a priest at Milan, and in various characters at Mantua, Ferrara, Bologna, Parma, and Venice, he made his first appearance in Paris on June 1, 1750. There his reputation had preceded him, and he was received with great favor; the marshal de Richelieu became his bosom friend; the duchess de Chartres doted upon him. After two years in Paris he joined his mother, who was then performing at the theatre of Dresden, and subsequently proceeded to Vienna, where he was received with much favor. On his return to Venice, July 25, 1755, he was lodged in the dungeons of the council of ten. He gives in his memoirs an entertaining but improbable account of the skill and audacity which he displayed in again effecting his escape. Early in 1757 he reappeared in Paris, where the dungeon episode added considerably to his notoriety. He now tried his hand at politics and financiering, and proposed a lottery in order to restore the equilibrium of the French exchequer. A meeting was convened to deliberate on the subject, and D'Alembert in his capacity of mathematician was invited to attend it.

Casanova's persuasive power convinced the most skeptical minds of the infallibility of his project; it was actually adopted, but he did not remain to observe its development, being sent as a kind of government spy to Dunkirk. On his return to Paris he met the famous adventurer, the count de St. Germain, whom he subsequently found installed at the Hague. After failing in his various industrial speculations at Paris, Casanova went to Holland under the auspices of the duke de Choiseul, to contract a loan for the French government, while St. Germain had received the same mission from the hands of Louis XV. himself. The two adventurers were well matched, but as they found the Dutch unwilling to advance any money, Casanova resumed his travels. At Roche, in Vaud, he paid his respects to Haller, and at Ferney to Voltaire. At London he met the chevalier d'Eon, and was introduced to George III., but, implicated in a charge of forgery, left the English capital in a hurried manner. At Brunswick the prince of Prussia helped him out of a pecuniary difficulty. His rencontres with St. Germain continued to be frequent and amusing.

At Sans Souci he had an audience of Frederick the Great; at St. Petersburg, of Catharine II. Prince Adam Czartorvski introduced him to the king of Poland, He returned to Vienna, but Maria Theresa would not receive him, and he departed for Spain. There his career forms a continued series of scandals and intrigues. In Barcelona he was put in prison, where he beguiled his time by writing Confutazione della storia del governo veneto d'Amelot de la Hous-sttye (Amsterdam, 1769). After recovering his liberty, he betook himself in 1768 to Aix, where he met Cagliostro. But Casanova's roving career was now drawing to its close. At a dinner of the Venetian ambassador at Paris he had met Count Waldstein of Bohemia, a good-natured man, and to escape from the dangers of his precarious position, he accepted the office of librarian in the chateau of the Bohemian count, where he spent the remaining years of his life. Casanova wrote a work on Polish history, translated the Iliad into French verse (4 vols. 4to, Venice, 1778), and was the author of an account of his imprisonment, and various other writings, among which is Ieosameron, ou Histoire d'Edouard et d"Elisabeth, a narrative of 80 years spent among the inhabitants of the interior of the globe (5 vols. 8vo, Prague, 1788-1800). But his literary fame rests upon his Memoires de ma vie jus-qu'en 1797, written during his residence in Bohemia (corrected ed., 8 vols. 8vo, Paris, 1830).