This retrograde movement left Mantua to itself. On the 3d of June Bonaparte's headquarters were at Verona,—a strongly fortified place bestriding the Adige, thus insuring an easy transit to either side of the river, and which derives further strategic importance from its topographical position. A number of spurs run south from the Tyrol along the Lake of Garda and fall into the plain at Verona, which thus stands at the foot of the valleys formed by them. On either side of this cluster of spurs lie the valleys of the Adige and the Brenta, the two probable lines by which an Austrian attack would come. Verona, therefore, was a central point with reference to any offensive movements of the enemy, and became the pivot upon which Bonaparte's strategy hinged. On the 4th of June Mantua was blockaded. Having now compassed his first objective, Bonaparte passed temporarily from the offensive to the defensive, ceased his advance, and occupied himself with assuring the line of the Adige and pressing the siege of Mantua.
There remained only to realize the political advantages gained by his wonderful successes. The Duke of Parma had entered into a convention on the 9th of May, followed in the same course on the 17th by the Duke of Modena. On the 5th of June the Court of Naples, startled out of its dream of security, signed an armistice, withdrawing its troops from the coalition and its ships from the British fleet,—a precipitate abandonment of the common cause as ill-judged as it was cowardly. At that very moment the French leader was writing, "I see but one means not to be beaten in the autumn; and that is, so to arrange matters that we shall not be obliged to advance into southern Italy."[128] The Pope still holding out, Bonaparte improved the time which the Austrians must need to prepare a new movement, by marching into the papal states a corps under Augereau, whom he followed in person. On the 19th Bologna was reached, and on the 24th the Pope signed an armistice. Coincidently with this advance, it was felt safe and opportune to send into Tuscany a division taken from the corps occupying Piedmont. This detachment entered Leghorn on the 28th of June, occupied the port despite the neutrality of Tuscany, drove out and broke up the great British commercial and naval interests centred there, and obtained a secure base for the intended attempt upon Corsica.