Why did the Greeks defeat the Persians?

The reasons for the victory of the Greeks over the Persians:

1. The presence of the Greeks of a well-trained and armed army, operating in a dense formation (phalanx);

2. The morale of the Greeks was higher as they defended their homeland;

3. The predominance in the Persian army of motley infantry detachments, with different weapons and often devoid of fighting spirit. They went into battle out of fear of the Persian king;

4. The Persians relied on cavalry, with which the Greek infantry successfully coped in the ranks;

5. The Persian infantry played an auxiliary role, therefore, acted separately, not forming any formations in battle.