On April 17, 1459, Galeazzo Maria Sforza, Count of Pavia and the eldest son of Francesco Sforza, Duke of Milan, arrived in Florence for a stay of just over two weeks. The stated purpose of his visit was to meet Pope Pius II, due to pass through Florence on his way from Rome to Mantua, and to provide the pontiff with sufficient escort for his difficult journey through the Romagna. The visit also created an opportunity for the fifteen-year-old Galeazzo Maria to meet Cosimo de’ Medici and the Signoria of Florence and thus add luster to the alliance between Florence and the Sforza, which had already contributed to the establishment of the Sforza as dukes of Milan and was to be a decisive factor in Italian diplomacy until the end of the fifteenth century.