Aleandro was a cardinal and opponent of Luther. He was a scholar and humanist, and was well-acquainted with Erasmus. He lectured at Venice, Orleans and Paris where he was appointed Rector of the University.

1519 – Vatican Librarian
1520 – Pope Leo X sends him to Germany to lead the opposition against Luther
1523 – Clement VII sends him as nuncio to the court of Francis I of France
1528 – Consecrated as bishop
1538 – Created cardinal by Paul III