I'm Greek, so:
Battle of Thermopylae was basically Greeks getting together to fend off those pesky Persians. Thermopyles is a mountain pass,
http://www.mlahanas.de/Greeks/Histor...hermopylae.gif .
They learnt that a HUGE Persian force was heading their way, they didn't have a chance against them. So, Spartans being Spartans, told the other Greeks to push back and they would stay and buy them time. There WERE more than those 1000 Greeks there, there were people from all over.
300 Spartans and 700 Thespieis stayed behind to fend off the Persians at the pass of Thermopylae. Xerxes sent wave after wave through the tight pass, but the better training and fighting spirit of the Greeks was too much for them, and the Persians were losing MANY troops, and the Greeks nearly none. At some point, the Persians fell back under the order of Xerxes. A Greek traitor, by the name of Ephialtes (meaning nightmare in Greek), told the Persians of another road leading to the pass through the mountains. With another path through to the Greeks, the Persian forces were able to pour more troops in, ultimately overcoming the brave protectors of Greece.
The "300" people keep going on about is just to make it a bit more interesting. What sounds better, those meaty Spartan fellas killing thousands of Persians and then succumbing, or being told about another 700 blokes who stood there with them, but who's city-state didn't do much else noteworthy?
Anyway, there you go.
The Battle of Salamis (naval battle) was another example of the Greek's war smarts, they used fewer, smaller vessels to obliterate the Persian warships.
That happened around the same time, if I remember correctly.
At the battle of Thermopylae, King Leonidas uttered the famous words "Molon Lave" which basically means "come and get them", after being told to surrender his weapons.
When Queen Gorgo says "Come back with your shield, or on it", they used to say "E tan i epi tas", in ancient Greek.
I'm in the army, at the moment, and it so happens that our division's coat of arms, so to speak, is the symbol of that historic battle.