The distribution of the cavalry into squadrons was that which Alexander found at his accession; but he altered it, when he remodelled the arrangements of his army (in 330 B. C.), at Susa, so as to subdivide the squadron into two Lochi, and to establish the Lochus for the elementary division of cavalry, as it had always been of infantry.[139] His reforms went thus to cut down the primary body of cavalry from the squadron to the half-squadron or Lochus, while they tended to bring the infantry together into larger bodies—from cohorts of 500 each to cohorts of 1000 men each. [139] Arrian, iii. 16, 19. Among the Hypaspists or Guards, also, we find an Agêma or chosen cohort, which was called upon oftener than the rest to begin the fight. A still more select corps were, the Body-Guards; a small company of tried and confidential men, individually known to Alexander, always attached to his person, and acting as adjutants or as commanders for special service. These Body-Guards appear to have been chosen persons promoted out of the Royal Youths or Pages; an institution first established by Philip, and evincing the pains taken by him to bring the leading Macedonians into military organization as well as into dependence on his own person. The Royal Youths, sons of the chief persons throughout Macedonia, were taken by Philip into service, and kept in permanent residence around him for purposes of domestic attendance and companionship. They maintained perpetual guard of his palace, alternating among themselves the hours of daily and nightly watch; they received his horse from the grooms, assisted him to mount, and accompanied him if he went to the chase: they introduced persons who came to solicit interviews, and admitted his mistresses by night through a special door. They enjoyed the privilege of sitting down to dinner with him, as well as that of never being flogged except by his special order.[140] The precise number of the company we do not know; but it must have been not small, since fifty of these youths were brought out from Macedonia at once by Amyntas to join Alexander and to be added to the company at Babylon.[141] At the same time the mortality among them was probably considerable; since, in accompanying Alexander, they endured even more than the prodigious fatigues which he imposed upon himself.[142] The training in this corps was a preparation first for becoming Body-guards of Alexander,—next, for appointment to the great and important military commands. Accordingly, it had been the first stage of advancement to most of the Diadochi, or great officers of Alexander, who after his death carved kingdoms for themselves out of his conquests.