Kythnos, one of the islands that belong to the Cyclades complex, has been the home of many settlers throughout the ages. Mesolithic remains a witness that the island may be the oldest settlement of the Cyclades. According to the writings of Herodotus, the first settlers of Kythnos was the ancient tribe Dryopes that occurred in the 13th century BC. During their occupation, they built Cyclopean walls and many temples. According to the myth, the island was named after the king of the tribe, Kythnos. The tribe has also given its name to one of the island's picturesque villages, Dryopis or Dryopida.
The history of Kythnos starts from the prehistoric times. Numerous old settlements were discovered around the island, one of the most famous found at the site of Vryokastro. This site is located above the bay of Episkopi, on the North West side of the island and is dated back to the 7th to the 5th centuries BC. The most significant finding from this inhabited site was an inner sanctum of a temple, which contained over 14,00 objects including jewels, gold, silver and bronze artifacts, it also contained terracotta figurines and decorated vases. This temple was believed to have been dedicated to Hera, the queen of the Gods, or to Aphrodite, the goddess of Love. The Cyclades chain of islands was very prone to pirate attacks, hence a lot of sites of the old settlements indicate extensive defense structures.
Most were surrounded by huge stone walls, or like the "Kastro", a settlement located in the extreme north, surrounded by a sheer 500 feet deep cliff on three sides and a narrow track barricaded by huge stone walls on the fourth. The village inside seems to have been plundered several times and rebuilt many times. During the Venetian era of Kythnos history, which began in 1207, this island came under the control of Frankish lord Marco Sanudo and remained under Venetian rule for nearly 400 years. The island was known as Thermia in those times and the capital was Kastro. It was famous for its hot mineral springs which were located on the north-eastern coast of the island, near the village of Loutra.
A Frankish fort was built in the capital, Kastro and was named the Tower of Thermia. The last Venetian lord Angelo Gozzadini was overthrown by the Turks in 1617, in a rather treacherous manner. It is noted that the Turks employed a woman with child and in pain requesting admittance into the capital. The watchman's daughter, taking pity on the woman's state opened the door for her, letting in the Turkish army hiding nearby. This tale still remains alive in popular island ballads. After the Turks took over Kythnos, it remained a religiously free but poor and backward island. However, this did not stop Kythnos from being one of the first islands to revolt against the Turks.
Under their first Greek King Othon, Kythnos became a place for exile for political prisoners. During the Second World War, the population of Kythnos dwindled again and the lack of a deepwater moor hampered the prospects of attracting tourists. Kythnos today is a prosperous, thriving island, which is becoming very popular with tourists. Ever since the construction of a new mole in 1974, Kythnos became much more accessible and thus more popular with tourists.