Worried about the growing ties between the Habsburgs and Russia, in 1524 Sigismund signed a Franco-Polish alliance with King Francis I of France to avoid a possible war on two fronts. Francis I himself was looking for allies in Central Europe to curtail the increasing power of Habsburg Emperor Charles V, whose realms were labelled "the empire on which the sun never sets". Furthermore, Queen Bona was instrumental in establishing an alliance between Poland and France, with the objective of recovering Milan. The official negotiations were conducted by Antonio Rincon in 1524, who was then followed by Jerome Laski. Through the agreement, the son of Francis, Henry, Duke of Orléans, was to marry one of Sigismund's daughters, and Sigismund's eldest son was to marry a daughter of Francis I.