Adventurer, spy, violinist, librarian, and, according to his Memoirs, one of the world's great lovers, who also tried it once with a man... Born in Venice, he served in the household of Cardinal Acquaviva, and embarked upon a career of intrigue and adventure which took him in many parts of Europe, especially to Paris, Rome, Berlin, Warsaw, and Madrid.

From 1774 he was a spy in the Venetian police service, but in 1755 he was shut in the Piombi prison in Venice, charged with trying to spread Freemasonry. He escaped from there and went back to France, where he introduced the State lottery. Assuming the title of "Seigneur de Seingalt" he resumed wandering through Europe.

In 1782 a libel got him into trouble, and after more wanderings he was appointed in 1785 Count Waldenstein's librarian at his castle of Dûx, in Bohemia, where he wrote his Memoirs (published 1826-38, althought the expurgated text did not appear until 1960-61).