Andros, an island of Greece, in the archipelago, the northernmost of the Cyclades, 21 by 8 m.; pop. in 1870, 19,674. It is mountainous, but has many fertile valleys, yielding wine, oil, silk, oranges, citrons, etc. Andro, or Castro, the capital, is situated on a shallow harbor on the E. coast; pop. 5,000. The Andri-ans submitted to the Persians in the invasion of Greece by Xerxes, and subsequently, after some resistance, to the Athenians. Still later, the island was successively annexed to Mace-don, Pergamus, and Pome.