After the cardinal's death, he moved to Padua, and completed there his literary apprenticeship under Sperone Speroni, Francesco Piccolomini and Scipione Gonzaga.
Between 1564 and 1587 he visited Venice, Bergamo, Verona, Rome, Viterbo, Perugia, Siena, Florence, Bologna, Ferrara, Reggio Emilia, Correggio, and Turin, where he became particularly known as a poet, composing various occasional poems for Charles Emmanuel I, Duke of Savoy.
[1] The first volume of his Lettere discorsive nelle quali in diverse opportune occasioni si danno utilissimi ammaestramenti intorno al regolato e leggiadro scriuer toscano, was published in Padua in 1584.
This chair, the first vernacular language professorship in Europe, was especially created to teach Italian to the many German students present in Siena at that time.
Most of Borghesi's extant philological works were written by him in epistolary form, and appear to have enjoyed some degree of popularity”.