Because the Persian army wanted to destroy individual Greek poli, so Athens convinced other poli to combine forces with them and make a league or an alliance in order to attack the Persian army and eventually win.
No. It defeated a Persian expeditionary force. Athens and Sparta were then friends. Pheidippides ran to Sparta to summon them to help, but the Spartans didn't arrive in time before the battle was fought.
Sparta and Athens were not rivals in 480 BCE - that came more than 30 years afterwards when the threat of Persia subsided. Sparta had promised to help them against the Persian attack on Athens in 490 BCE, but its army had arrived on the battlefield at Marathon too late. They remained on good terms and were natural allies in the Persian invasion in 480-479 BCE, providing the two largest contingents to the southern Greek coalition, led by Sparta, which repelled the invasion. Even if Athens had not been friendly with Sparta, it had no choice because it was a prime target of the Persian invasion and needed all the help it could get. It was not a case of Athens joining force with Sparta, it was Athens seeking the help of Sparta and its allies. They remained close allies for another 20 years, Athens helping Sparta put down a rebellion in its territory. They fell out when Athens started interfering in the affairs of the Peloponnesian League cities (which Sparta led) and Athens ignored Sparta's appeal to back off, leading to an all-out war.
Nowhere. Athens sent Pheidippides to run to Sparta to summon them to help fight the Persians. The 120 mile return trip killed him.
Pheideppides. He died hallucinating on his return at the end of the 120 mile return trip.
Alliances in Greece changed. For example several times Sparta and Athens fought on the same side, at others on opposing sides. Similarly at times Sparta and Thebes fought together, at other times were opponents. Generally Sparta was allied to other Doric city-states, though again this was not a hard and fast rule. And although Persia was usually an opponent of the Greek city-states, it was Persian financial support which enabled Sparta and its allies to get a competent fleet in the Peloponnesian War and defeat Athens.
Allies Sparta and Athens had a falling out when the Spartan helots revolted and the forces Athens sent to help Sparta began to side with the revolutionaries, and Sparta sent them home. Athens turned the Delian league it had led against the Persian Empire into an empire of its own, and began to interfere in the cities of the Peloponnesian league led by Athens resulting in open war.
Athens and Sparta, along with other Greek city-states, fought against Persia during the Greco-Persian Wars, which primarily took place from 499 to 449 BCE. Key battles include the Battle of Marathon in 490 BCE and the Battle of Salamis in 480 BCE. While both city-states played significant roles, Athens was particularly prominent in naval engagements, while Sparta excelled in land battles. Their collaboration was crucial in repelling Persian invasions.
The one of 480-479 BCE.
Both.
Yes.
hello my name is chris!!!!
They each provided major forces for a coalition of southern Greek city-states to resist the Persian invasion. After the invasion was repelled, Sparta left the follow-up action to Athens. They remained allies until Athens converted the anti-Persian alliance into an empire of its own after the Persians gave up trying to enforce peace in the western Mediterranean. Athens over-reached itself and this led to the Peloponnesian War between a Spartan alliance and Athens and its empire. In this war Persia gave assistance to Sparta to help it defeat Athens.