Having endeavoured to determine the theoretical establishment of the auxiliary regiments, it remains to discover how far this corresponded to the actual strength at which they were maintained, and here our evidence is scanty, and likely to remain so. Fortunately, the discovery in Egypt of some of the official papers of the Cohors I Augusta Praetoria Lusitanorum has thrown some light on the question. On January 1, 156, this regiment had on its books 6 centurions, 3 decurions, 114 mounted infantry, 19 camel-riders (_dromedarii_), and 363 infantry, making, with the _praefectus_, a total of 506 men. Between January and May, 18 recruits were enrolled, 15 infantry, an _eques_, a _dromedarius_, and a decurion.[61] These figures agree fairly well with the arrangement suggested above, although the _dromedarii_ are an additional complication, and the regiment appears even to have exceeded its ‘paper-strength’. This, however, may be easily accounted for if we imagine that a number of men had served their term and were about to be discharged. Unfortunately, this document remains isolated, and further evidence is not likely to be forthcoming. _Conditions of service._ Questions concerning the method of enlistment for the auxiliary regiments are reserved, on account of their connexion with the broader issues raised by the whole recruiting system, for discussion in a later section. For the present it will be sufficient to discuss the conditions of service in this branch of the army, as they are laid down in the so-called _diplomata militaria_.[62] These documents, of which we possess some 70 or 80 examples dealing with the auxilia, are small bronze tablets, issued originally to individual soldiers, recording the privileges granted to them either after their discharge or after they had completed a term of 25 years. The reason for this variation seems to be that while the _praemia militiae_ were always conferred after the regulation number of years had been served, it was often the practice to retain the men with the colours for some years longer before finally discharging them. This practice, which we hear of in the early empire as a standing grievance of the legionaries,[63] seems to have prevailed also among the auxilia during the first century.[64] After 107, however, we have no instances of the _praemia_ unpreceded by discharge, a change which is probably due to the perfection of organization, and can be traced also in the legions.