Built for the Pisani doges in 1756 , with 200 rooms , Tiepolo frescoes in the ballroom , and vast park with pond , labyrinth , and stables , it was purchased by Napoleon in 1807 and subsequently hosted Tsars , Hapsburg emperors , and , for their first meeting in 1934 , Hitler and Mussolini .
A 1756 building was purchased by Napoleon in 1807 .