In 1565, as we have seen, Francis, Cosimo's son, married and was installed in the Palazzo Vecchio, and it was then that Vasari was called upon to construct the Passaggio which unites the Palazzo Vecchio and the Pitti, crossing the river by the Ponte VecchioCosimo's idea (borrowed it is said from Homer's description of the passage uniting the palaces of Priam and Hector)