For seventy-three days he pressed his assaults with the utmost fury and persistence. He brought up battering rams and huge wooden towers constructed for him by Roman deserters; and on one occasion he succeeded in surprising one of the towers upon the river frontage, but the seventy picked archers who occupied it were overwhelmed by the garrison and slain. At last he breached the walls; and though some of the garrison (including the historian Ammianus) cut their way through his lines on the further side, and thus succeeded in escaping, the rest, with all the inhabitants, were massacred in the ensuing storm. Yet Amida had at least performed the duty which is ordinarily expected of a fortress. It had held back the tide of invasion for the period of a whole campaign. Sapor had lost a third of his army; and the season was too far advanced for any further operations. He retreated again into Persia, and abandoned the city that he had won. An even more notable siege occurred in the year 502. King Kobad, the father of the yet mightier Chosroes I. invested the city that autumn; assailing it from the western side (as Sapor had done before him), and employing similar siege engines to those of his predecessor's days.[21] The garrison caught the blows of his rams on reed mattresses lowered from the ramparts, and greased the drawbridges of his wooden towers so effectively that the stormers could not cross. Also they employed "winged words" of such singular virulence and pungency as to scandalize even their own historian.[22] He felt obliged to draw the line at "Lime-house," though boiling oil and firebrands were fair. "If the bishop had still been alive he would never have permitted it;" and indeed when the women took to stripping themselves on the ramparts, and taunting the besiegers with their inability to sack the place, we may grant that any bishop would have had good cause to protest! Kobad next "cast a mount" against the walls in the manner of Sargon and Sennacherib; a huge incline of earth and brushwood to give his men access to the parapet. The besieged breached their own wall under it, and secretly drew away the core; propping the cavity with balks of timber, and then filling it with combustibles. When the assault began they fired their mine; and an hour or two later the mound collapsed beneath the feet of the attacking columns, precipitating the luckless stormers into the blazing furnace below.[23] Three months had passed in vain assaults, and Kobad had made no progress. His thinly clad Persians were suffering terribly from the winter cold; and the Great King swallowed his dignity and offered to raise the siege for half a crown! But success had made the defenders more insolent than ever, and they scorned even this show of homage. They retaliated by sending him a bill for the vegetables which his army had consumed out of their gardens. This was too much for Kobad, and he resolved to fight to a finish. Three days later the laugh was on his side.