With the few ships and men at his disposal, Pisani recognized that it was out of the question to lead a successful attack; but he knew that if he could defer the issue there was a Venetian fleet in the eastern Mediterranean which, learning his straits, would return with all possible speed to his aid. He therefore determined to force the enemy to remain where they were without offering open battle, and this manœuvre he carried out with great boldness and skill, sinking heavy vessels loaded with stones in the channels that led to Chioggia, while placing his own fleet across the main entrance to prevent Genoese reinforcements. The blockaders were now blockaded; and through long winter days and nights the rivals, worn out by their bitter vigil, starving and short of ammunition, watched one another and searched the horizon anxiously. At length a shout arose, for distant sails had been sighted; then as the Venetian flag floated proudly into view the shout of Pisani and his men became a song of triumph: the Republic was saved. Venice was not only saved from ruin, her future as Queen of the Adriatic was assured, for the Genoese admiral was compelled to surrender, and his Republic to acknowledge her rival’s supremacy of the seas. The sea-policy of Venice was the inevitable result of her geographical position; but as the centuries passed she developed a much more debatable land-policy. Many mediaeval Venetians declared that since land was the source of all political trouble, therefore Venice should only maintain enough command over the immediate mainland to secure the city from a surprise attack. Others replied that such an argument was dictated by narrow-minded prejudice, a point of view suitable to the days when Lombardy had been divided amongst a number of weak city states, but impracticable with powerful tyrants, such as the Visconti, masters of North Italy. Unless Venice could secure the territories lying at the foot of the Alps, and also a wide stretch of eastern Lombardy, she would find that she had no command over the passes in the mountains by means of which she carried on her commerce with Germany and Austria. The advocates of a land-empire policy received confirmation of their warnings when in the early part of the fourteenth century Mastino della Scala, lord of Vicenza, Padua, and Treviso, attempted to levy taxes on Venetian goods passing through his territories. The Republic, roused by what she considered an insult to her commercial supremacy, promptly formed a league with Milan and Florence against Mastino, and obtained Treviso and other towns as the result of a victorious war.