 But Eugene, while making ostentatious preparations to enter Italy by the Adige or Lake Garda or the Brescia road, secretly reconnoitred passages over the mountains between Rovereto and the Vicenza district.On 27 May, taking great precaution as to secrecy, and requesting the Venetian authorities to offer no opposition so long as his troops behaved well, Eugene began his march by paths that no army had used since Charles V's time, and on the 28 May his army was on the plains.His first object was to cross the Adige without fighting, and also by ravaging the duke of Mantua Charles IV's private estates (sparing the possessions of the common people) to induce that prince to change sides.