many civil wars, they could grow to number several thousand men. In effect, the bucellarii were small private armies equipped and paid by wealthy and influential people. As such they were quite often better trained and equipped, not to mention motivated, than the regular soldiers of the time. Originating in the late fourth century, they increased in importance until, in the early Byzantine army, they could form major elements of expeditionary armies. Notable employers of bucellarii included the magistri militiae Stilicho and Aetius, and the Praetorian Prefect Rufinus. Foederati Outside the regular army were substantial numbers of allied forces, generally known as foederati (from foedus = "treaty") or symmachi in the East. The latter were forces supplied either by barbarian chiefs under their treaty of alliance with Rome or dediticii. Such forces were employed by the Romans throughout imperial history e.g. the battle scenes from Trajan's Column in Rome show that foederati troops played an important part in the Dacian Wars (101–6). In the 4th century, as during the Principate, these forces were organised into ill-defined units based on a single ethnic group called numeri ("troops", although numerus was also the name of a regular infantry unit). They served alongside the regular army for the duration of particular campaigns or for a specified period. Normally their service would be limited to the region where the tribe lived, but sometimes could be deployed elsewhere. They were commanded by their own leaders. It is unclear whether they used their own weapons and armour or the standard equipment of the Roman army. In the late army, the more useful and long-serving numeri appear to have been absorbed into the regular late army, rapidly becoming indistinguishable from other units. Recruitment Romans During the Principate, it appears that most recruits, both legionary and auxiliary, were volunteers (voluntarii). Compulsory conscription (dilectus) was never wholly abandoned, but was generally only used in emergencies or before major campaigns when large numbers of additional troops were required. In marked contrast, the late army relied mainly on compulsion for its recruitment of Roman citizens. Firstly, the sons of serving soldiers or veterans were required by law to enlist. Secondly, a regular annual levy was held based on the indictio (land tax assessment). Depending on the amount of land tax due on his estates, a landowner (or group of landowners) would be required to provide a commensurate number of recruits to