Tyre succumbed to the attack of Alexander of Macedonia who had blocked the straits by a dike. First a Greek city, and then a Roman city were constructed on this site, which is now a promontory. The historic role of Tyre declined at the end of the period of the Crusades. Criterion (vi): Tyre is associated with the important stages of humanity. They are however highly vulnerable to lack of conservation and to development pressures that could weaken their ability to convey fully the significance of Tyre as powerful port city.