The most difficult challenge Alexander the Great faced was during the siege of Tyre on his journey toward Egypt. Conquering Tyre was essential to protect the rear of Alexander's army from potential Persian attacks. Tyre was a fortified island city of the Phoenicians, situated about 1 km from the mainland, with a fort wall 150 feet tall. The Phoenicians were skilled shipbuilders. Tyre was protected by fortifications towering approximately 150 feet high. With a history of repelling numerous aggressions, the Tyrians believed their defenses to be impenetrable. Alexander inherited his father’s throne, commanded the full strength of the Macedonian army, and was educated by Aristotle, which made him one of the greatest warriors of all time. He employed siege warfare tactics, utilizing siege engines like the catapult, siege tower, and battering ram. He also utilized his army on both land and sea, which led to the seven-month siege of Tyre from January 332 BC to July 332 BC, which became one of his greatest victories. The siege was marked by relentless attacks and counterattacks from both sides. The new city of Tyre was about 3/4 km away from the mainland, and Alexander built a unique causeway. He constructed a 1-kilometer-long and 200-foot-wide causeway, as described by Diodorus, over a natural land bridge less than two meters deep, enabling his army to approach the city's formidable walls.