In summer 1356, Louis invaded Venetian territories without a formal declaration of war. He laid siege to Treviso on 27 July. A local nobleman, Giuliano Baldachino, noticed that Louis sat alone while writing his letters on the banks of Sile River on each morning. Baldachino proposed the Venetians to assassinate him in exchange for 12,000 golden florins and Castelfranco Veneto, but they refused his offer because he did not share the details of his plans with them. Louis returned to Buda in the autumn, but his troops continued the siege. Pope Innocent VI urged the Venetians to make a peace with Hungary.