In the 19th Century, Hydra was home to some 125 boats and 10,000 sailors. The mansions of the sea captains that ring the harbor are a testament to the prosperity that shipping brought to the island which, at the date of the Revolution, had 16,000 inhabitants. During the Greek Revolution, the fleets of Hydra and the other two naval islands of Psara and Spetses were able to wrest control of the Eastern Aegean Sea from the Ottoman Empire. When the Greek War of Independence broke out, Hydra's contribution of some 150 ships, plus supplies, to fight against the Turks played a critical role. The Greek admiral Andreas Miaoulis, himself a settler on Hydra, used Hydriot fire ships to inflict heavy losses on the Ottoman fleet. With the end of the revolution and the creation of the Greek state, the island gradually lost its maritime position in the Eastern Mediterranean, igniting an economic crisis which led to a period of hardship and unemployment. The main reason was that with the creation of the Greek state, its fleet lost the privileges which the Treaty of Küçük Kaynarca and the use of the Russian flag gave it. Another reason was that the traditional families who owned the majority of the fleet failed to foresee the benefits in participating in the steam ship revolution that significantly cut shipping operational costs through reduced crew and independence of the winds, putting them at a disadvantage vis-á-vis the new shipping companies of Piraeus, Patras and Syros. A third reason was that the new conditions made illegal activities such as piracy impossible. Once again many of the inhabitants abandoned Hydra, leaving behind their large mansions and beautiful residences, which fell into ruin. The mainstay of the island's economy became fishing for sponge. This brought prosperity again, at least until 1932 when Egypt forbade fishing along its coast. By the Second World War the Hydriotes were again leaving the island; many of them went abroad.