Thence he went into Phrygia, passing by the lake called Ascania,[190] in which salt is naturally concreted. The natives use this salt, and do not need the sea at all for this article. On the fifth day of his march, he arrived at Celaenae,[191] in which city there was a fortified rock, precipitous on all sides. This citadel was occupied by the viceroy of Phrygia with a garrison of 1,000 Carians and 100 Grecian mercenaries. These men despatched ambassadors to Alexander, promising to surrender the place to him, if succour did not reach them by a day which had been agreed upon with them, naming the day.[192] This arrangement seemed to Alexander more advantageous than to besiege the fortified rock, which was inaccessible on all sides to attack. At Celaenae he left a garrison of 1,500 soldiers. Remaining here ten days, he appointed Antigonus, son of Philip,[193] viceroy of Phrygia, placed Balacrus, son of Amyntas[194] as general over the Grecian allies in place of Antigonus, and then directed his march to Gordium.[195] He sent an order to Parmenio to meet him there with the forces under his command; an order which that general obeyed. The newly-married men also, who had been despatched to Macedonia, now arrived at Gordium, and with them another army which had been levied, and put under the command of Ptolemy, son of Seleucus,[196] Coenus, son of Polemocrates, and Meleager, son of Neoptolemus. This army consisted of 3,000 Macedonian foot-soldiers and 300 horse-soldiers, 200 Thessalian cavalry, and 150 Eleans under the command of Alcias the Elean. Gordium is in the Phrygia which lies near the Hellespont, and is situated upon the river Sangarius, which takes its rise in Phrygia, but, flowing through the land of the Bithynian Thracians, falls into the Euxine Sea. Here an embassy reached Alexander from the Athenians, beseeching him to release to them the Athenian prisoners who had been captured at the river Granicus, fighting for the Persians, and were then in Macedonia serving in chains with the two thousand others captured in that battle. The envoys departed without obtaining their request on behalf of the prisoners for the present. For Alexander did not think it safe, whilst the war against the Persian was still going on, to relax in the slightest degree the terror with which he inspired the Greeks, who did not deem it unbecoming for them to serve as soldiers on behalf of the foreigners against Greece. However, he replied that whenever his present enterprise had been successfully achieved, they might then come as ambassadors to treat on behalf of the same persons.[197] BOOK II. CHAPTER I. CAPTURE OF MITYLENE BY THE PERSIANS.—DEATH OF MEMNON.