Marchetti, Giovanni an Italian ecclesiastic of note, was born at Empoli, in Tuscany, in 1753, of humble parentage. After struggling for years to secure the advantages of a thorough education, he entered the priesthood in 1777. Later he took up the pen in defense of the rights of the Roman see. His works, which made him known as a brilliant writer and a learned student, attracted the attention of pope Pius VI, who accorded him a pension and invested him with different offices. In 1798, after Rome had been proclaimed a republic, he was banished. In 1799 he was conducted to Florence, where he endured imprisonment for one month. On his return to Rome (1800) he opened an academy of theology'. When the excommunication of the emperor Napoleon by Pius VII became known (1809), Marchetti and cardinal Mattel, accused of aiding the pope in this violent part, were imprisoned in the castle of St. Angelo. Some time after Marchetti obtained permission to go to his native town. He returned to Rome in 1814; in 1822 was appointed vicar of Rimini; in 1826 became secretary of the Assembly of Bishops, and died Nov. 15, 1829. Among his works, which have been translated into many languages, we find Saggio critico sopra la Storia
Ecclesiastica di Fleury (Rome, 1780, 1.2mo): — Critica della Storia Ecclesiastica e de' discorsi di Fleury (Bologne, 1782, 2 vols. 12mo): — Esceritazioni Ciprianiche circa il battesino degli eretici (Rome, 1787, 8vo): — Del concilio di Sardica (Rome, 1785, 8vo): — I Christianesimo dimonstrabile sopra i suoi libri (Rome, 1795, 8vo): — Strattesnimenti diJfanmillia sulla storia della religione con le sue prove (Rome, 1800, 2 vols. 8vo):La Providenza (Rome, 1797, 12mo): — Metamzorfosi ver" dute da Basilide l'eremita sul terminare del secolo xviii (Florence, 1799, 8vo): — Il si ed il no, parallelo delle doctrine e regole ecclesiastiche (Rome, 1801, 8vo): — Lezioni sacre dall' ingresso del popolo di Dio in Cananea fino alla schiavitiu di Babilonia (Rome, 1803-8, 12 vols. 8vo): — Della Chiesa quanto alto stato politico della citta (Rome, 1817-18, 3 vols. 8vo): — La vita razionale dell' uonzo (Rome, 1828, 8vo). He also contributed many articles to the Generale lecclesiastico (Rome) from 1788 to 1798. See Hoefer, Nouv. Biog. Generale, 33:491.