Alexander's capture of Tyre was not as important as the battles at Issus or Gaugamela, but the city was vital to Alexander's larger plans and the siege shows how adept the Greeks were at this type of warfare.
Tyre was on an island off the coast of modern Lebanon, far enough from the mainland that the water was 18' deep. With mammoth walls, a fortified harbor, and virtually no land outside the walls, the city was long thought impregnable.
Alexander needed the city, to control the Eastern Mediterranean and provide him a secure port through which to funnel reinforcements and supplies. For, the Greeks ruled the sea.
His initial attempts to take the city failed. He quickly enough cut the city off from supply, but Tyre knew he was coming, had stocked up on supplies, and had its own fresh water. He tried bombarding the walls with catapults mounted on the decks of ships. He tried placing siege towers on ships, bringing them right up to the walls, but the citizens sank the ships with great boulders.
Finally, Alexander resolved on an ambitious approach. He could only take the city by getting his soldiers close enough to let his huge siege engines do their damage. To this end, Alexander ordered his engineers to build a mole -- a land bridge from the mainland to the island. It was 200' wide and took months to complete.
When it was ready, he brought his siege engines along it to the walls. The citizens now fought desperately, and the Greeks were repeatedly driven back. But the city was running out of food and, after a seven month siege, Tyre fell. Alexander was so furious that this one city had halted his progress for so long, that he gave the city over to plunder and his soldiers sacked it without mercy.
The siege of Tyre had a lasting effect, for the mole stayed, silted up, and today Tyre is connected to the mainland. Alexander, in his drive to conquer, permanently changed the face of the land. It is deeds like these that drive the many legends of Alexander and made him famous from his day to ours.
