Echinousa is also a recorded name of the island during the ancient times, probably because of the snake Echidna (viper), being common even today on the island. Since the ancient era, it was a battlefield between Ancient Athens, the ruler of the island, and Sparta, the ruler of Milos. In the Middle Ages it was known as Argentiera (Greek: Αρτζεντιέρα), because of the silver-colored rocky lands of its southern coast.