Why was Sparta a rival of Athens?

Answer 1

The were not always enemies. They were when Persia invaded mainland Greece 480-479 BCE. Yet during the war between Athens and its allies and Sparta and its allies (431-404 BCE) the Persians provided the money for Sparta to raise a fleet to match the dominant Athenian one, resulting in Athens' final defeat.

Necessity and opportunity make strange bedfellows.

Answer 2

They were initially allies. Then Athens headed the anti-Persian league after the Persian invasion was repelled. Athens used this league to further its own influence and wealth, and interferd in the business of the Dorian city-states, which set up the Peloponnesian Leabue with Sparta as its leader to counter the Athenian empire.

Answer 3

Originally they were friends and allies. Sparta responded to Athens' appeal to help repel the Persian attack on it at Marathon but arrived too late. They joined together at Salamis and Plataia. As late as the 460s Athens assisted Sparta to put down a rebellion in its territory.

The division came thereafter when Athens forced 180 cities into an empire of its own and began to interfere in the affairs of Sparta's allies in the Peloponnesian League, resulting in the 27-year Peloponnesian War which Athens lost and was stripped of it's empire. Thereafter Sparta and Athens were involved in Greek wars as both allies and adversaries at various times. This was the nature of the Greek city-states - alliances were temporary, warfare was permanent.

Answer 4

Because Persia tried to attack Greece many times, and did not succeed. Macedon and the other Greek states decided to take revenge and conquered Persia to teach them a lesson.