Marco I Sanudo

Marco Sanudo (c. 1153 – c. 1227) was a Venetian adventurer who founded the Duchy of the Archipelago. Maternal nephew of Doge Enrico Dandolo, he took part in the Fourth Crusade in 1204 and helped negotiate Venice's purchase of Crete. Between 1205 and 1207 he raised a fleet and conquered Naxos and other Cycladic islands. He built his capital of Kastro and kept the Greek archontes in possession of their lands and religion.

He became a vassal of the Latin Emperor Henry around 1210 or 1216 and fought the Empire of Nicaea for him. He died around 1227 and was succeeded by his son Angelo.