In antiquity, the island possibly was the island Glaukonisos that was referred by Pliny. Around the islands, some wrecks have taken place. There are wrecks of ancient ships but the most famous is the wreck of steamship Himarra in 1947. The steamship Himarra sank few metres southwest of Kavalianni and overall 385 people drowned. It was the most deadly wreck in the modern Greek history. The first owner of the island was doctor Dimitrios Bellos. Bellos family is still the owner of Kavalliani and the small island Koukistra north of Kavalliani.
Source: wikipedia.org