Birth. Ca. 1290, Milan. Son of Matteo I Magno Visconti, prince of Milan, and Bonacosa Borri.

Education. (No information found).

Early life. Canon of the cathedral chapter of Milan. Abbot of S. Ambrogio, Milan. He had two illegitimate children, Leonardo and Margherita Visconti.

Episcopate. In 1317, the metropolitan cathedral chapter of Milan elected him archbishop; Pope John XXII did not confirm the election; the pope named instead Aircardus Antimiani as archbishop; Giovanni administered de facto the archdiocese of Milan; the legitimate archbishop was impeded most of the time and died in August 1339; Givanni was tghen elected archbishop again by the metropolitan cathedral chapter; he was confirmed by the pope on July 17, 1342; occupied the see until his death. In 1323, the pope excommunicated Giovanni, who had been accused of heresy; Giovanni allied himself with Antipope Nicholas V.

Cardinalate. Created pseudocardinal deacon of S. Eusebio in the consistory of January 19 (or 20), 1329. He made his submission to Pope John XXII by procurator on September 15, 1329, and in person on November 26, 1329; he was never promoted to the cardinalate. Elected bishop of Novara, August 1, 1331; on November 20, 1331, received permission to prorogate his episcopal consecration. Consecrated between December 23, 1331 and May 18, 1332. Co-signore of Milan, together with is brother Luchino, from August 1339; at the death of the latter in January 1349, Giovanni became signore of Milan; his work was very important in the expansion and organization of the Milanese state. e obtained Bologna in October 1350; by a compromise with the Holy See, in 1352, he ceded his signoria over the city in exchange to becoming papal legate to the same for twelve years. Signore of Genoa and of Novara in 1353.

Death. October 5, 1354, Milan. Buried in the metropolitan cathedral of Milan, together with Archbishop Ottorino Visconti of Milan; his monument was sculpted by an anonymous Campionese master; it originally was in the church of S. Tecla, Milan; a Latin poem is sculpted on it, signed by a Sabino de' Zamorei, from Parma, and dated 1354.

Bibliography. Chacón, Alfonso. Vitæ, et res gestæ Pontificvm Romanorum et S. R. E. Cardinalivm ab initio nascentis Ecclesiæ vsque ad Vrbanvm VIII. Pont. Max. 2 volumes. Romae : Typis Vaticanis, 1677, II, col. 444-453; "Essai de liste générale des cardinaux. Les cardinaux du XIVè siècle jusqu'au Grand Schisme". Annuaire Pontifical Catholique 1930. Paris : Maison de la Bonne Presse, 1930, p. 147-148; Eubel, Conradus and Gulik, Guglielmus van. Hierarchia Catholica Medii Aevi. Volumen I (1198-1431). Münich : Sumptibus et Typis Librariae Regensbergianae, 1913; reprint, Padua : Il Messagero di S. Antonio, 1960, pp. 17, 332 and 372.