In the 350s b.c. Philip I assumed the throne of Macedon, a relatively poor province north of Greece. He developed a first-class army and, taking advantage of the temporary weakness of Athens (Greece's dominant city-state) after the Social War (358-55), began conquering Athenian-dominated provinces on the Greco-Macedonian frontier. While the Greek polises continued their almost constant squabbling, Philip extended Macedonian control over areas to Macedon's north, then he attacked Greece itself. In 338 b.c. Philip's army defeated an Athenian-Theban alliance at Leuctra, giving him mastery of the Greek peninsula. He established the Hellenic League the following year, uniting almost all the Greek polises into an alliance aimed at defeating the Persian Empire. As the forces of the Hellenic League prepared to cross the Hellespont into Asia Minor in 336, Philip was assassinated and succeeded by his son Alexander.

In spite of the fact he was only twenty years old, Alexander won the immediate loyalty of his father's Macedonian army due to tutelage at his father's side and his valor at the battle of Leuctra. The rest of the League was not as true, however. While putting down rebellions in the north, Alexander learned that Athens had bolted the League, thinking him dead. He returned to Athens very much alive and reinforced his authority; he then turned to continue his father's plan of invading Persia. Educated by Aristotle, Alexander was both a brilliant scholar and a Greek "nationalist"; he aimed not only to defeat Persia and avenge the destruction they had inflicted on Greece in the invasion of Xerxes (480-79 b.c.) but to spread Greek culture and knowledge wherever he went.

He quickly established a reputation as a courageous and innovative general. In 333 b.c. he began his invasion of Asia Minor, defeating armies sent against him by local Persian governors or by the Persian Emperor Darius III. At Issus late in the year Alexander's 30,000 soundly defeated Darius' army three times that size while losing but 450 men. Alexander's strategy was to take control of the eastern Mediterranean coastline. He had no fleet while the Persian navy could roam at will, harassing his supply lines and provoking revolts in Greece. Denying the Persians their ports would force them to either abandon the eastern Mediterranean or defect to the Macedonian cause. His first conquest was simple. Sidon surrendered without a fight, for it had long suffered under Persian dominance. Its sister city Tyre, however, had profited from a Persian alliance and was determined to hold out against the invaders while Darius rallied another army inland.

Alexander's army marched to Tyre sometime in January 332. He spoke with the city elders, expressing a desire to worship their god Melkart, a Phoenician version of Heracles. When they suggested he worship in Old Tyre, where there was a better temple, he took it as an insult and prepared his attack.

Tyre was well situated to withstand a siege. It was built on an island half a mile offshore, making direct assault without a fleet extremely difficult. Two harbors served the city, meaning that supplies could be brought in at will. Further, Tyre had ties to Carthage, which promised to send assistance in case of attack. Having no ships meant Alexander's forces could approach the city only one way: if they could not walk on water, they would have to build a causeway.

Although neither his staff nor army favored his idea, Alexander began dismantling the city of Old Tyre and placing the stones in the water. He scoured the countryside for timber for piling for the causeway, manpower, and supplies. This was an unbelievably massive engineering feat, for Alexander ordered that the causeway be built 200 feet wide. At first the Tyrians jeered the effort, then began to worry as the Greeks moved ever closer. The first counterstroke came with eight Tyrian ships sailing in close to the workers and pelting them with massed archery fire. In response, Alexander built towers to place his archers in a commanding position in case a similar attack was attempted. Instead, in the next foray the Tyrians launched a massive fire ship into the mole at the point where the towers were built; in the confusion smaller vessels landed commando parties that killed laborers on shore and destroyed Alexander's siege engines.

This lightning raid would have broken the spirit of a lesser man than Alexander, but he ordered the causeway widened and new towers built. He knew, however, that he needed protection from these naval attacks. Alexander reasoned that in the wake of his victory at Issus he would attract widespread support, and he was correct. Ships from Cyprus, Byblos, and Rhodes sailed to join with the Sidonian fleet and Alexander soon had almost 225 vessels. He drafted engineers from Phoenicia and Cyprus to construct siege artillery on the decks of barges and transports. As they were building, Alexander led an expedition into the hills to beat back marauders who had been harassing his timber crews and his supply lines. He returned to Sidon with his position secure and a fleet far larger than that of the isolated city. He arrived to find more good news: 4,000 mercenaries from Greece had arrived to swell his ranks. He boarded a Macedonian galley and set sail for Tyre.

The Tyrian admiral rowed out for a naval battle, but upon seeing Alexander's massive fleet he changed his mind and fled for his home port. The allied ships gave chase but the Tyrians narrowly reached port and blocked the harbor mouth with all their ships facing side by side, showing nothing but bows and rams. Alexander did not press the attack, but placed his Cypriot ships in a blockade.

Freed from any naval interference, Alexander's laborers made rapid progress with the mole. A summer storm battered his causeway, but he placed untrimmed cedars on the windward side and they acted as a breakwater. After the storm passed, Alexander soon found himself within range of the city to employ his catapults, with archers and slingers placed forward to keep the tops of the walls clear. Similarly, the siege engines that had been built on barges began pounding the walls from the seaward side. The Tyrians responded by placing skins on the walls to absorb some of the shock, then building backup walls. Their archers attempted to keep the attackers at bay with flaming arrows, but the seaward assault was showing positive effects. A planned night amphibious assault had to be canceled owing to bad weather. The landward side of the city, however, had the strongest walls and was resisting well.

Alexander had floating platforms moor right beside the walls in order to use rams against them. The Tyrians responded by dropping large blocks into the shallows so the barges could not get close enough. They began building weapons for the upcoming hand-to-hand combat that would commence when the causeway reached the city walls. Then, after having so much go their way, the Tyrians learned that the promised aid from Carthage would not be coming. Meanwhile, the hand-to-hand combat was beginning outside the walls. Alexander's ships brought up derricks to remove the blocks dropped from the city, and Tyrian divers attacked, cutting the lines and ships' anchor cables. It was a temporary setback for the Macedonians, who replaced the anchor lines with chains. Finally, after six months, Alexander's causeway reached the city.

He brought up siege towers 150 feet in height and he rolled them close enough to drop drawbridges onto the walls. The fighting was fierce, with the Tyrians pouring red-hot sand and gravel onto the attackers, forcing a retreat. After beating back a naval sally, Alexander sailed around the island city looking for the weakest point. He chose to assault the walls at the mouth of the northern harbor and brought up his barge rams and catapults to begin the barrage. It failed to break through. Undaunted, he moved his assault ships to the southeastern face, near the Egyptian harbor, and finally began to see the walls crumble. He threw in an assault team that was beaten back by a hail of arrows. Still, he knew this was the crack he had been looking for. On 31 July he threw in his crack troops, and when their commander was killed Alexander charged in himself. He led forces along the battlements while his ships broke through into the harbor, landing more troops within the city. Rather than be caught between two forces, the soldiers withdrew into the city center and made a last stand at the shrine of Agenor.

After such a long and arduous siege, Alexander did nothing to restrain his troops in their moment of victory. Pillage, loot, rape, and murder were the order of the day. The only saving grace for any of the citizens came from Alexander's allied troops from Sidon, who took pity on the inhabitants and smuggled about 15,000 of them out of the city. Tyre's King Azimilik with his advisers sought refuge in the temple of Melkart, and Alexander spared them. When the blood lust finally paled, 30,000 citizens survived only to be sold into slavery. Beforehand, however, Alexander crucified 2,000 men of fighting age. He then proceeded to sacrifice to Melkart as he had originally requested, following the service with a massive feast, games, and naval review.

The operation of 332 b.c. was the first truly amphibious assault in history, with the Macedonians having to develop the tactics that would be followed to modern times: preparatory bombardment, combat swimmers, obstacle removal, and fire support and harassing fire from offshore vessels. Even the use of ramps off the ships for unloading assault troops began here.

Alexander's capture of the city did indeed deny Persia one of its primary harbors, but the slaughter that ensued only impressed some of the other cities. When his forces reached Gaza, they again had to besiege the city, and the resulting aftermath was as bloody as that in Tyre. Possession of the city gave Alexander the ability to secure his supply lines overland from Macedon, as well as supplement them with naval transport. His forces pressed southward into Egypt, where they spent the winter of 332/331. There, Alexander established a new city that he named after himself (the first of many) and apparently received a revelation that he was directly descended from Apollo. From then on he assumed an increasingly divine demeanor, and accomplishments like the causeway at Tyre certainly did little to diminish his ego. The link between land and island over time has widened; the southern harbor has filled with silt and the island of Alexander's day is the end of peninsula with the foundation laid by Macedonian engineers more than 2,300 years ago.