When Alexander destroyed Tyre, most of the towns on the route to Egypt quickly capitulated. A later tradition recorded his entry into Jerusalem: according to Josephus, Alexander was shown the Book of Daniel's prophecy, presumably chapter 8, which described a mighty Greek king who would conquer the Persian Empire. He spared Jerusalem and pushed south into Egypt. However, Alexander met with resistance at Gaza. The stronghold was heavily fortified and built on a hill, requiring a siege. When "his engineers pointed out to him that because of the height of the mound it would be impossible... this encouraged Alexander all the more to make the attempt". After three unsuccessful assaults, the stronghold fell, but not before Alexander had received a serious shoulder wound. As in Tyre, men of military age were put to the sword and the women and children were sold into slavery. Alexander advanced on Egypt in later 332 BC, where he was regarded as a liberator. He was pronounced son of the deity Amun at the Oracle of Siwa Oasis in the Libyan desert. Henceforth, Alexander often referred to Zeus-Ammon as his true father, and after his death, currency depicted him adorned with rams horn as a symbol of his divinity. During his stay in Egypt, he founded Alexandria-by-Egypt, which would become the prosperous capital of the Ptolemaic Kingdom after his death. 
How many assaults did it take to capture the stronghold?
2