[243] Callisthenes the historian, who accompanied Alexander into Asia, states that the breadth of the plain between the mountain and the sea was not more than fourteen stadia, or a little more than one English mile and a half. See _Polybius_, xii. 17. [244] These seem to have been foreign mercenaries. See _Polybius_, v. 79, 82; _Strabo_, xv. 3. Hesychius says that they were not a nation, but foreigners serving for pay. [245] Callisthenes—as quoted in _Polybius_, xii. 18—reckoned the Grecian mercenaries of Darius at 30,000, and the cavalry at 30,000. Arrian enumerates 90,000 heavy-armed, not including the cavalry. Yet Polybius tries to prove that there was not room even for the 60,000 troops mentioned by Callisthenes. [246] “The depth of this single phalanx is not given, nor do we know the exact width of the ground which it occupied. Assuming a depth of sixteen, and one pace in breadth to each soldier, 4,000 men would stand in the breadth of a stadium of 250 paces; and therefore 80,000 men in a breadth of twenty stadia. Assuming a depth of twenty-six, 6,500 men would stand in the breadth of the stadium, and therefore 90,000 in a total breadth of 14 stadia, which is that given by Kallisthenes. Mr. Kinneir states that the breadth between Mount Amanus and the sea varies between one and a half mile and three miles.”—_Grote._ [247] _Diodorus_ (xvii. 31), and Plutarch (_Alex._, 18), give the same number; but _Justin_ (xi. 9) says the Persians numbered 400,000 infantry and 100,000 cavalry. It took five days for them to cross the Euphrates, over bridges of boats (_Curtius_, iii. 17). The money alone of the king required 600 mules and 300 camels to convey it (_Curtius_, iii. 8). [248] Cf. _Arrian_, iii. 11; and Xenophon (_Anab._, i. 8, 21, 22). [249] See Donaldson’s _New Cratylus_, sect. 178. [250] Cf. Xenophon (_Cyropaedia_, vii. 1, 6). [251] In describing the battle of Arbela, Arrian mentions eight distinct squadrons of Macedonian heavy cavalry, which was known by the name of the Companions. Among the squadrons several, if not all, were named after particular towns or districts of Macedonia, as here, Anthemus, and Leuge. We also find mention of the squadrons of Bottiaea, Amphipolis, and Apollonia. See also _Arrian_, i. 2; i. 12; iii. 11. [252] τῇ γνώμῃ δεδουλωμένος. An expression imitated from _Thucydides_, iv. 34; compare _Arrian_, iii. 11; v. 19; vi. 16, where the same words are used of Porus and the Indians. [253] κυμῆναν τῆς φάλαγγος. An expression imitated from Xenophon (_Anab._, i. 8,18). It is praised by Demetrius (_De Elocutione_, 84). Krüger reads ἐκκυμῆναν. Cf. Plutarch (_Pompey_, 69). [254] _Curtius_ (iii. 29) says that on Alexander’s side 504 were wounded, and 182 killed. _Diodorus_ (xvii. 36) says, that 450 Macedonians were killed. _Justin_ (xi. 9) states that 280 were slain.