The centre of the second line was occupied by a body of phalangite infantry, formed of companies, which were drafted for this purpose from each of the brigades of their phalanx. The officers in command of this corps were ordered to be ready to face about, if the enemy should succeed in gaining the rear of the army. On the right of this reserve of infantry, in the second line, and behind the royal horse-guards, Alexander placed half the Agrian light-armed infantry under Attalus, and with them Brison's body of Macedonian archers, and Cleander's regiment of foot. He also placed in this part of his army Menidas's squadron of cavalry, and Aretes's and Ariston's light horse. Menidas was ordered to watch if the enemy's cavalry tried to turn the flank, and if they did so, to charge them before they wheeled completely round, and so take them in flank themselves. A similar force was arranged on the left of the second line for the same purpose, The Thracian infantry of Sitalces was placed there, and Coeranus's regiment of the cavalry of the Greek allies, and Agathon's troops of the Odrysian irregular horse. The extreme left of the second line in this quarter was held by Andromachus's cavalry. A division of Thracian infantry was left in guard of the camp. In advance of the right wing and centre was scattered a number of light-armed troops, of javelin-men and bowmen, with the intention of warding off the charge of the armed chariots. [Kleber's arrangement of his troops at the battle of Heliopolis, where, with ten thousand Europeans, he had to encounter eighty thousand Asiatics in an open plain, is worth comparing with Alexander's tactics at Arbela. See Thiers's "Histoire du Consulat," &c. vol. ii. livre v.] Conspicuous by the brilliancy of his armour, and by the chosen band of officers who were round his person, Alexander took his own station, as his custom was, in the right wing, at the head of his cavalry: and when all the arrangements for the battle were complete, and his generals were fully instructed how to act in each probable emergency, he began to lead his men towards the enemy. It was ever his custom to expose his life freely in battle, and to emulate the personal prowess of his great ancestor, Achilles. Perhaps in the bold enterprise of conquering Persia, it was politic for Alexander to raise his army's daring to the utmost by the example of his own heroic valour: and, in his subsequent campaigns, the love of the excitement, of "the rapture of the strife," may have made him, like Murat, continue from choice a custom which he commenced from duty. But he never suffered the ardour of the soldier to make him lose the coolness of the general; and at Arbela, in particular, he showed that he could act up to his favourite Homeric maxim.