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
Arkoi that calls at the island, as well as occasional small ferries to other nearby islands such as Marathi. Arkoi Arkoi (; also Arkioi, Αρκιοί) is a small Greek island which is part of the Dodecanese archipelago. It is situated in the eastern Aegean Sea, close to the Turkish Aegean Coast. The island belongs to the municipality of Patmos, and has a population of 54 inhabitants at the 2001 census. The small population means that there is no real capital, but most inhabitants live close to the main harbour with the rest living scattered around the island on higher ground. The