History of Heraklia
It is a small island with just 115 inhabitants and belongs to the Small Eastern Cyclades complex. It is situated between Ios and Naxos in the eastern edge of the complex. Herakleia extends over 1800 km2 and has rich vegetation, many spring waters, small hills, scenic bays and old pathways. It is the ideal place for peaceful vacations. Its coasts offer shelter to Monachus monachus seal and Caretta caretta sea turtle. It consists of two settlements; Aghios Georgios (island's port) and Panagia.
The island is so small that it probably never really suffered under any kind of oppressive power except pirates, which, of course, was bad enough.
Heracleia was probably a Cretan - Minoan settlement in the 2nd Millenium BC, since there is a city of the same name on Crete. It could also have had some sort of worship of Heracles, since that is what the name of the island means.
Taxes were collected from both the Venetian and Turkish rulers, but apart from that, the island was pretty much left to it self. The Kastro does indicate though that people lived here under Ventian rule.
The island also belonged to the monastery of the Virgin Mary (Panagia) Chozoviotissa on Amorgos during the Middle Ages.