At the division of the Byzantine Empire, Spetses was given over to the rule of the Venetians, who were replaced by the Turks in 1460. Some time later came the Arvanite refugees from the Peloponnesus, who settled at first in the bays of Ag. Anargyri and Zogheria.
These new Spetsiots started out with just livestock, but quickly realized that there was a demand for the timber that came from the island's pines, and so began to build small ships to transport it. A second wave of refugees arrived in 1540, and the ships being built on the island grew in number and in size. After 1715, the small community which had established itself at Kastelli began to take shape as the mighty naval power which was to take part in the Orloff Insurrection in the second half of the 18th century. In retaliation for the Spetsiots' raising of the Russian flag, Turks and Albanians set fire to Kastelli in 1770, and many were killed or taken prisoner. When the first Russo-Turkish war ended in 1774, the prisoners were released and they returned to the island. The Spetses fleet now sailed under the safeguard of the Russian flag, and the island was in effect independent. It was governed by an 8-man council of elders, a local administrator and Turkish representatives appointed by the Spetsiot elders. This was a period of rapid economic expansion for the island, given further momentum by the outbreak of the Napoleonic Wars. The people of Spetses became extremely wealthy during this time, enough so as to allow them luxuries undreamed of in other parts of Greece, such as private tutors for their children.