The advanced season of the year when the vizir disembarked in Candia, and the disorganized state of the forces which he found there, prevented the immediate commencement of offensive operations; but in the course of the winter, the arrival of the contingents of Egypt and Africa, as well as of a squadron with fresh troops from Constantinople, raised his army to between 40,000 and 50,000 effective men; and on the 20th of May 1667, the trenches were once more opened in form on the western side of the city, while 300 pieces of cannon, thundering from the Ottoman lines, covered the approaches of the pioneers.[16] Of the seven[17] great bastions which formed the principal defences on the land side, those of Panigra, Bethlehem, and Martinengo, were the chief points of attack; the vizir himself taking post opposite the first, while the Beglerbeg of Anatolia and the Pasha of Egypt were stationed against the Bethlehem and the Martinengo. The assault, as on former occasions, was conducted chiefly by the slow process of sap and mine; but the superior skill of the Christian engineers, enabled them frequently to explore and countermine the works of the enemy; and the mining parties were thus surprised and blown into the air, while murderous combats took place under ground, from the accidental rencounters of the soldiers employed in these subterranean galleries. The garrison, which had at first numbered about 12,000, under the command of the Marchese di Villa, a Piedmontese officer of approved skill and courage, received, at the end of June, a reinforcement of 1000 veteran troops, brought by the Venetian Captain-General Morosini, who arrived with the fleet at the Isle of Standia, off the entrance of the port; and a concourse of volunteers, from all parts of Europe, hastened to share in the defence of this last bulwark of Christendom in the Grecian seas; while the Maltese, Papal, and Neapolitan galleys cruised in the offing, to intercept the supplies brought by sea to the Ottoman camp. The Turks, meanwhile, with their usual stubborn perseverance, continued to push their sap under the ravelin of Mocenigo, and the Panigra bastion which it covered; and though their progress was retarded, and their works often ruined, by the sallies of the defenders, the foundations were at length shaken, and the ramparts rent and shattered, by the explosion of innumerable mines; and the janissaries, fired with fanatic zeal, and stimulated by promises of reward, rushed again and again to the attack under the eye of the vizir. "Many and various," says Rycaut, in his quaint narrative, "were the valiant assaults and sallies, the traverses extraordinary, the rencounters bloody, the resistance vigorous, not known or recorded in any siege before;" and the struggle continued with unabated fury on both sides, till the approach of winter; while, after each unsuccessful assault, the Venetians, emulating the ferocity of their enemies,