Whom did the Greeks fight?
The Greek states often fought each other. Sparta and Athens fought a long war, called the Peloponnesian War, from 431 to 404 BC. Sparta won. Only the threat of invasion by a foreign enemy made the Greeks forget their quarrels and fight on the same side. Their main enemy was Persia.
The wars against Persia lasted on and off from 490 to 449 BC. The Persian kings tried to conquer Greece and make it part of the Persian Empire. In the end, it was Greece which defeated Persia, when Alexander the Great defeated the Persian Empire in the 330s BC.
The Battle of Marathon
The Battle of Marathon was a famous Greek victory against the Persians. About 10,000 Greeks, mostly from Athens, fought an army of 20,000 Persians led by King Darius. The Greeks surprised their enemies by charging downhill straight at the Persians.
Marathon is remembered for the heroism of a Greek named Pheidippides. Before the battle, he'd run for 2 days and nights - over 150 miles (240 km) - from Athens to Sparta to fetch help. Then he fought at Marathon. After the battle, he ran 26 miles (42 km) non-stop to Athens, but died as he gasped out the news of victory. The modern Marathon race is over the same distance as his epic run from Marathon to Athens.
Fighting in formation
The backbone of the Greek army was the hoplite. He was a foot-soldier, and his weapons were a long spear and a sword. He also had a round shield. Hoplites fought in lines or ranks. Eight to ten ranks made a formation called the phalanx. Each soldier held his long spear underarm. Enemy soldiers saw only a mass of spears and shields, that was hard to break through - and hard to stop once it started moving forward. Lots of phalanxes massed together became like a giant human tank. The Greeks had archers and cavalry, but it was the phalanx that won many famous battles.
What armour did Greek soldiers wear?
A hoplite had to pay for his armour, unless his father was killed in battle. Then he was given his father's weapons and armour. Rich men had metal armour, shaped to the chest, but others wore cheap armour made of linen cloth. Layers of cloth were glued together, to make a tough, bendy jacket, which could be covered with metal plates.
A Greek soldier carried a big round shield, made of wood and metal. On his legs he wore metal guards, called greaves. On his head he wore a metal helmet, often with a crest on top. The crest was usually made of horsehair, and stuck up to make the soldier look taller and fiercer.