Two City-States were the most influential, those being Athens and Sparta
Athens was the first state to establish democracy, with Cleisthenes as its founder. Only men could vote however.
Sparta however had a monarchy, its most notable leader being King Leonidas
Athens was very intellectual in terms of their government, with Athenians learning in the Athenaeium
Sparta however had a school named the Agoge, teaching only to be a strong and fearless warrior.
Darius I wanted to conquer all of Europe so he attacked Greece through Thrace (modern day Bulgaria)
The Persian Empire was large enough to have an army worth 1.2 million men
The first army to rebel against the Persians was the City-State of Miletus
Miletus asked Athens for help, and so Athens sent help but were bribed by the Persians to go home, leading to Miletus destruction.
The Persians were planning to capture Athens by splitting its army into two, one in Athens and the other in the Battle of Marathon.
Pheidipeddis was a runner who was sent by the general at Marathon to run back to Athens to warn them of Persian invasion.
Pheidipeddis went to Sparta to ask for help, but they rejected him so he ran back to the general and back to Athens. His last words when he arrived at Athens was "victory"
Darius' son Xerxes took control of the army and planned to launch round two, but this time against the Spartans.
The Persians tried to see if they could bribe King Leonidas, but instead he declared war.
King Leonidas brought only 300 men to the Battle of Thermopylae, fighting valiantly and fiercely, however because of a betrayal they were outflanked and killed.