XLIV.  He himself, with a few picked troops, now invaded Hyrkania, where he discovered an arm of the sea, which appeared to be as large as the Euxine, or Black Sea, but not so salt.  He was unable to obtain any certain information about it, but conjectured it to be a branch of the Maeotic lake.[416] Yet geographers, many years before Alexander, knew well that this, which is entitled the Hyrkanian or Caspian Sea, is the northernmost of four gulfs proceeding from the exterior ocean.  Here some of the natives surprised the grooms in charge of his horse Boukephalus, and captured the animal.  Alexander was much distressed at this, and sent a herald to make proclamation that unless his horse were restored to him, he would massacre the whole tribe with their wives and children.  When, however, they brought back his horse, and offered to place their chief cities in his hands as a pledge for their good behaviour, he treated them all with kindness, and paid a ransom for the horse to those who had captured it.

XLV.  From hence he passed into Parthia, where, being at leisure, he first began to wear the Persian dress, either because he thought that he should more easily win the hearts of the natives by conforming to their fashion, or else in order to try the obedience of his Macedonian soldiers and see whether they might not, by degrees, be brought to pay him the same respect and observance which the kings of Persia used to exact from their subjects.  He did not, however, completely adopt the Persian costume, which would have been utterly repugnant to Grecian ideas, and wore neither the trousers, the coat with long sleeves, nor the tiara, but his dress, though less simple than the Macedonian, was still far from being so magnificent or so effeminate as that of the Persians.  He at first only wore this dress when giving audiences to the natives of the country, or when alone with his more intimate friends, but afterwards he frequently both drove out publicly and transacted business in the Persian dress.  The sight greatly offended the Macedonians, but yet they were so filled with admiration for his courage, that they felt he must be indulged in his fancies about dress; for besides all his other honourable wounds, he had only a short time before this been struck by an arrow in the calf of his leg, so that splinters of the bone came out, and also received such a blow upon his neck from a stone, that his eyesight was affected for a considerable time afterwards.  Yet he did not cease to expose himself to danger, but crossed the river Orexartes, which he himself thought to be the Tanais or Don, and, although suffering from an attack of dysentery, defeated the Scythians and chased them for many miles.