In 480 BC, King Xerxes of Persia was enroute to attempt to conquer Greece when he encountered a huge and damaging storm near Skiathos. (These waters are often choppy and turn many a tourist a bit green around the gills.) Xerxes put in for repairs to his ships and built a pillar of stone in the reef of Myrmes to warn others of the dangers there. History counts this as the first-known navigational aid. You can still see part of this famous pillar in the Naval Cadel School in Piraeus.
Later, the Gizzi ruled the island and built the fort on Bourtzi islet. The present town near the fort was settled by refugees from Evia. The Skiathot navy fought against the Ottomans at Cesme and against the Turks in 1805.
The most famous native is the novelist Alexandros Papadiamantis. He wrote more than 100 novelas and short stories, including The Gypsy, The Murderess, and The Man Who Went to Another Century. All his novels are set in island life.
In high season this island rents its body and soul to tourism and neon. Visit off season if you want a less touristy experience.