The siege of Tyre was carried out by Alexander the Great in 332 BC during his campaigns against the Persians. At first, the Macedonian army was unable to capture the city of Tyre, which was a strategic coastal base on the Mediterranean Sea, through conventional means because it was on an island that was 1 kilometer off the coast of modern-day Lebanon and had walls right up to the sea. Alexander responded by first blockading and besieging Tyre for seven months and building a causeway. When his soldiers discovered that they could not extend it any further due to a steep drop under the surface of the water, he ordered siege towers with catapults at the top to be moved to the end. This allowed him to breach the fortifications.