Dodecanese relative quiet and prosperity. In 408 BC, the three cities of Rhodes had united to form one state, which built a new capital on the northern end of the island, also named "Rhodes"; this united Rhodes was to dominate the region for the coming millennia. Other islands in the Dodecanese also developed into significant economic and cultural centers; most notably, Kos served as the site of the school of medicine founded by Hippocrates. However, the Peloponnesian War had so weakened the entire Greek civilization's military strength that it lay open to invasion. In 357 BC, the islands were conquered by
Italian Islands of the Aegean Social Republic, but were "de facto" subject to the German military command. After the end of World War II, the islands came under provisional British administration. In the Treaty of Peace in 1947, the islands were ceded to Greece. Italian Islands of the Aegean The Italian Islands of the Aegean (; ) were a group of twelve major islands (the Dodecanese) in the southeastern Aegean Sea, which — together with the surrounding islets — were ruled by the Kingdom of Italy from 1912 to 1943 and the Italian Social Republic from 1943 to 1945. The Dodecanese, except Kastellorizo, were occupied