Ottoman control was largely absent in the mountainous interior of Greece, and many fled there, often becoming brigands. Otherwise, only the islands of the Aegean and a few coastal fortresses on the mainland, under Venetian and Genoese rule, remained free from Ottoman rule, but by the mid-16th century, the Ottomans had conquered most of them as well. Rhodes fell in 1522, Cyprus in 1571, and the Venetians retained Crete until 1670. The Ionian Islands were only briefly ruled by the Ottomans (Kefalonia from 1479 to 1481 and from 1485 to 1500), and remained primarily under the rule of Venice.