Hydra has been inhabited since pre historic times and some believe it was the home of the Hydra - the water-snake which Hercules encountered and combated in his second labor. Not much is known about the island's ancient history, it appears to be completely ignored by the Byzantine chroniclers, but it played an important role in the 15th century, when people from the mainland and the islands sought refuge here from attacking pirates and Turks.
In the 17th century it started to be settled by big numbers of refugees from Turkish rule on the mainland, mostly Alba-nians, who were soon active in the reviving commerce of Peloponnese. After the abortive insurrection of 1770, Hydra received a further influx of refugees; and the inhabitants, too numerous for their island to support them, took increas-ingly to seafaring, at first in the Aegean islands, but later as far as Alexandria, Constantinople, Trieste and Venice, and eventually to France and even America. The Turks left them in peace, though requiring them to provide ships and sailors for the Turkish fleet. That was a period of economical prosperity, control of piracy and internal peace. Due to the Otto-mans great shipping requirements, Hydra made great progress in shipping and trade. Fabulous European styled mansions were constructed giving the island its aspect of today. The Hydrian merchants apart from their goods brought to the is-land many revolutionary European ideas as well.
Hydra had an important fleet in the 18th century and it was sometimes called "Little England" because of its European flare and commerce. It was one of the strongest islands during the war of Independence which began in 1821, and contributed with its huge fleet of 130 ships. Thus, Argosaronikus, insignificant until this period, numbered 27,000 inhabitants. This demographic explosion had positive and negative consequences regarding social progress. The most positive being, were the development of trade and the rapid progress of shipping. Thereafter, the island continued its fishing industry and concentrated on sponge fishing until the demand for sponges declined. The island then endured a relatively brief period of stagnation until the early 1950s, when it was discovered by painters, and tourism then became its number one industry. Today the island of poets, writers and painters, the unique jewel of Argo Saronic Gulf, Henry Miller's and Leonard Cohen's Hydra is a protected historical and architectural wonder.