After receiving a training in the humanities at Modena under the Cistercian Varino of Piacenza, he devoted himself to the study of jurisprudence for five years, first at Bologna, then at Padua, and graduated as doctor of laws at the early age of seventeen.
His thorough knowledge of the Latin and Greek languages induced Cardinal Giovanni de' Medici, the future Pope Leo X, to take him into his service and afterwards appoint him legal auditor in the Papal Curia.
Desirous of leading a more quiet life, Cortese resigned this office and in 1507 entered the Benedictine monastery of Polirone near Mantua, one of the most flourishing abbeys of the recently founded Cassinese Congregation.
When de' Medici heard that his former auditor had become a monk, he addressed a letter to him expressing his surprise and his displeasure at the step which Cortese had taken and urging him to leave the monastery and resume his former occupation in Rome.
In his answer to the cardinal's letter Cortese states that great dangers beset his soul when he was still engaged in worldly pursuits, and speaks of the interior happiness which he experienced while chanting the Divine praises and applying himself to the study of Holy Scripture.
When in 1513 de' Medici ascended the papal throne as Leo X, Cortese sent him a letter of congratulation in which, however, he did not omit to remind the new pontiff of his duty to begin at last general reform of the Church.
His health, however, was greatly impaired during his sojourn there, so that in 1527 he considered a change of climate indispensable and asked the superior of the congregation for permission to return to Italy.
He counted among his friends Gasparo Contarini, Reginald Pole, Jacopo Sadoleto, Pietro Bembo, Gian Matteo Giberti, and many other Humanists and ecclesiastical dignitaries.