The Cardinal of Lorraine and the Cardinal Camerlengo Ascarno Sforza had previously visited the Tuscan Court, and had received Cosimo’s consent to his son’s acceptance of the biretta.
Giovanni Battista Adriani in his Istorie di Suoi Tempe, has placed on record that this youthful Prince of the Church was “of mature judgment and wise beyond his years, and of such a bearing that it would have been difficult to have found anyone more attractive, more seemly in his morals, and very sensible.” In Rome Giovanni gave himself up especially to the study of antiquities, and he became a great favourite with the many pious, learned, and distinguished men who were gathered round the mild and religiously-minded Pontiff.
Cardinal de’ Medici’s secretary was the erudite and upright Abbot Felice Gualterio, who subsequently gathered together his letters and literary compositions, “wherein are noble and benevolent expressions of his affection for his father and mother and his brothers and sisters.” Garzia, two years his junior, is often named with sincerest love and pleasure.
Pius, constant in his devotion to the young Cardinal, added to his honours and prerogatives by creating him, early in 1561, Archbishop of Pisa, but, inasmuch as he had not reached the age prescribed for holding ecclesiastical preferments, Canon Antonio da Catignano was appointed Administrator of the spiritualities of the See. However, in March, the young Archbishop made his ceremonial entry into Pisa, accompanied by the Duke and Duchess, with their family and court.
The Pope greatly desired that Cardinal Giovanni should enter Holy Order, and to this the young prince cordially and reverently acceded, but, for reasons of his own, Cosimo declined his consent, remarking that “a prince of his house was more distinguished than a consecrated prelate.” As a set-off to this discourteous reply to Pius, the Duke, whilst at Pisa, founded the military order of San Stefano, as a thank-offering for the subjugation of Siena, much after the pattern of the Knights of Malta—constituting himself Grand Master and the Cardinal, Chancellor.
Giovanni actually undertook his duties as Archbishop by granting letters of appointment to benefices within his diocese. One is dated 24th October, 1562, and was addressed to the Bishop of Arezzo, about the presentation to a certain abbey which had become vacant upon the death of Cardinal della Cueva.
It was at this period that Pius wrote to Duke Cosimo, suggesting a matrimonial alliance between the Duke’s eldest son, Don Francesco,—who was undertaking a princely tour of the chief European Courts for the double purpose of making himself known personally to the various Sovereigns, and of looking out for a suitable consort,—and the Princess Maria Garzia of Portugal. The proposition was backed up by an offer of the kingly title to the Duke. Both propositions fell to the ground, but Pius, in his eagerness to render the Duke of Florence homage, and to prove his gratitude, asked his acceptance, for his young son Garzia, of the command of a Papal ship of war.