Tolomeo Gallio was a cardinal and Italian Catholic archbishop. He was named cardinal by Pope Pius IV, and was one of the two main consecrators of Cardinal Carlo Borromeo, Archbishop of Milan and Pope Clement VII.
The Gallio family belonged to the nobility of Como. The young Tolomeo (the real name was Bartolomeo) dedicated himself to classical studies under the guidance of Benedetto Giovio, who then sent him to Rome to his brother Paolo, Bishop of Nocera. In the Papal seat, he was at the service of Cardinal Trivulzio, then Cardinal Taddeo Gaddi, and finally Cardinal Gian Angelo Medici, the future Pius IV who, even after rising to the Throne of Peter, held him as his secretary.
In 1560 Tolomeo Gallio became bishop of Martorano, and two years later, on 6 July 1562 he became archbishop of Manfredonia. On 15 March 1565 he was proclaimed cardinal by Pope Pius IV, the bishop of the diocese of Terracina, Priverno and Sezze mons. Francesco Beltramini, granted in emphyteusis the privately owned land of San Martino, in which he built the Villa Gallio or Castle of San Martino, his summer residence, much loved by the Cardinal as evidenced by the correspondence he held with Carlo Borromeo. The following year, after the death of Pius IV, he returned to the diocese of Manfredonia.
In 1572 the appointment was made to Secretary of State by Pope Gregory XIII, the Bolognese Ugo Boncompagni and for 13 years, until 1585 Tolomeo Gallio was Secretary of State of the Apostolic See. In 1575 he commissioned the architect Pellegrino Tibaldi to build the building in Cernobbio, his native town, of what would later be called Villa d'Este, now the site of international congresses of the highest level. From 8 January 1581 to 9 January 1582 he was Camerlengo of the Sacred College. In 1583, on October 15, in Como, the Pontifical College Gallio was founded with papal bull Immensa Dei providentia. Even today, after more than 400 years, the Collegio Gallio works in the education sector. In 1580 it was invested by Philip II of the "Tre Pievi" County (Gravedona, Sorico and Dongo). In 1586 on the shores of Lake Como, over the remains of a fortress destroyed in the twelfth century, he built his "house of delight"; it is Palazzo Gallio in Gravedona where according to an uncertain tradition the Ecumenical Council, which was then the famous Council of Trent, should have been kept.
In 1587 he was created Cardinal bishop of Albano. In 1595 he bought the county of Alvito, which later became the Duchy of Alvito, giving rise to the construction of Palazzo Gallio, completed in 1633 by his nephew, Francesco Gallio, who founded a dynasty that will govern the duchy for about 200 years until Napoleonic period. The years from 1603 to 1607 saw Cardinal Gallio as Dean of the Sacred College.
Tolomeo Gallio died in Rome on the night between 3 and 4 February 1607 at the age of 79. He was buried in Santa Maria della Scala, one of the churches restored by himself.