Sparta was eventually the victor of the conflict but at a terrible price to Greece. The Peloponnesian War began in 431BC and ended in 404BC. The Peloponnesian War is broken up into three phases. Phase one (431BC-421BC) is known as The Archidamian War which ended in a stalemate. Phase two (421BC-415BC) erupted from a 6 year truce which was broken by military skirmishes.
This led to constant warfare between the leagues formed by the Greek city-states and Macedon. Around 221 BCE, Phillip V of Macedon took power of the Macedonian throne. He was considered to be the last Greek ruler who was militaristically and politically capable of uniting all of Greece. However, in 218 BCE, he allied with Carthage, which was a big mistake to his plans. This led to the breakout of wars between Rome and Macedon in a series of skirmishes.
This military strength helped Sparta defeat Athens and emerge victorious from the Peloponnesian War between 431-404 BC. However, this victory was at great cost. The subsequent defeat by Thebes in 371 BC Battle of Leuctra ended Sparta’s prominent role in Ancient Greece. Despite the loss of control, Sparta managed to maintain political independence until the Roman conquest of Greece in 146 BC. This led to a long period of decline for the once powerful Sparta.
Athens had trade interest in the Ionian region. So Athens encouraged the Ionians when they revolted against Persia in 499 BC. This enraged Darius and he led the 1st Greco-Persian war and was defeated in 490 BC in the battle of Marathon. His son, Xerxes led the 2nd invasion against Athens. In the meantime, the Athenians convinced the Greek city states that Persia was a serious security threat for the whole region and formed an alliance against the Persians.