Minôs acquired great nautical power, and expelled the Karian inhabitants from many of the islands of the Ægean, which he placed under the government of his sons on the footing of tributaries. He undertook several expeditions against various places on the coast—one against Nisus, the son of Pandiôn, king of Megara, who had amongst the hair of his head one peculiar lock of a purple color: an oracle had pronounced that his life and reign would never be in danger so long as he preserved this precious lock. The city would have remained inexpugnable, if Scylla, the daughter of Nisus, had not conceived a violent passion for Minôs. While her father was asleep, she cut off the lock on which his safety hung, so that the Krêtan king soon became victorious. Instead of performing his promise to carry Scylla away with him to Krête, he cast her from the stern of his vessel into the sea:[526] both Scylla and Nisus were changed into birds. [526] Apollodôr. iii. 15, 8. See the Ciris of Virgil, a juvenile poem on the subject of this fable; also Hyginus, f. 198; Schol. Eurip. Hippol. 1200. Propertius (iii. 19, 21) gives the features of the story with tolerable fidelity; Ovid takes considerable liberties with it (Metam. viii. 5-150). Androgeos, son of Minôs having displayed such rare qualities as to vanquish all his competitors at the Panathenaic festival in Athens, was sent by Ægeus the Athenian king to contend against the bull of Marathôn,—an enterprise in which he perished, and Minôs made war upon Athens to avenge his death. He was for a long time unable to take the city: at length he prayed to his father Zeus to aid him in obtaining redress from the Athenians, and Zeus sent upon them pestilence and famine. In vain did they endeavor to avert these calamities by offering up as propitiatory sacrifices the four daughters of Hyacinthus. Their sufferings still continued, and the oracle directed them to submit to any terms which Minôs might exact. He required that they should send to Krête a tribute of seven youths and seven maidens, periodically, to be devoured by the Minôtaur,[527]—offered to him in a labyrinth constructed by Dædalus, including countless different passages, out of which no person could escape. [527] Apollodôr. iii. 15, 8.