First, Alexander was good at protecting his people. Alexander had really good military strategies. He was very smart, and even waited almost two years waiting to attack the Persians so he could make sure everything was safe.“Alexander had great military strategies.” (Alexander The Great) Him having great military makes him a hero because he always protected his people.
Second, he gave them freedom because he gave them freedom. When he conquered places, he gave them a choice. The choice was to either join part of his growing empire or not join and your city would