What is Alexander's greatest legacy?

Alexander the great's greatest legacy is the vast cultural diffusion that resulted from his conquests, which spread Hellenistic culture across three continents. His establishment of cities, particularly Alexandria in Egypt, became centers of learning and trade, blending Greek and Eastern influences. This cultural exchange fostered advancements in art, science, and philosophy, significantly shaping the development of Western civilization. Additionally, his military tactics and strategies continue to influence military leaders and historians to this day.