1. Athens forms an Alliance I. Delian League A. An alliance formed by Athens 2. Formed because of invasions from the Persian Empire 3. Persian invasions threatened Athens’ independence and success 1. Alliance: a formal agreement that where people/states agree to work together

2. B. Organization 1. Many Greek city states joined Delian League 2. League was a defense pact to protect city states from another invasion 3. Athens became most dominant member in alliance 4. Members paid money to Athens for their protection

3. Sparta forms an Alliance II. Peloponnesian League B. By the sixth century Sparta was most powerful city in Peloponnesus A. Sparta located in southeast Greece in Peloponnesus region 1. Around 550 Spartans created alliance called Peloponnesian League

4. B. Purpose : create a force to protect Greece against enemies 1. Alliance helped Athens defeat Persia during the Persian Wars C. Conflict 1. Athens continued to gain power and Sparta felt threatened 2. So, Peloponnesian League tried to find ways to hold back Athens’ influence

5. Athens versus Sparta III. Peloponnesian War A. Rival between Athens and Sparta grew 1. Sparta issued an ultimatum : Athens must free all cities under its control or else there would be war 2. Athens refused and fighting with Sparta began

6. B. Important war facts 1. Fighting lasted for 27 years 2. Sparta invaded Athens during second year in war causing Athenians to gather inside the city’s walls for protection a. At the same time, a plague struck Athens that quickly spread in the overcrowded city killing many people

7. C. Outside help 1. Persian Empire provided Sparta with assistance to beat Athens 2. Persians aided Sparta in building stronger ships for battle 3. Athens suffered because of this and surrendered in 404 B.C. a. Now, Athens were forced to tear down walls that surrounded their city

8. D. Conclusion 1. After the war, Sparta ruled all of Greece for a short time 2. Over time, city state called Thebes became the leader in Greece 3. Fighting emerged against Thebes later causing a weakening of Greece