In the 4th century, the Roman army underwent a radical restructuring. In the rule of Diocletian (284–305), the traditional Principate formations of legiones, alae and cohortes appear to have been broken up into smaller units, many of which bore a variety of new names.Goldsworthy (2003) 206 Under Constantine I (r. 312–337) it appears that military units were classified into three grades based on strategic role and to some extent quality: palatini, elite units normally part of the exercitus praesentales (imperial escort armies); comitatenses, higher-grade interception forces based in frontier provinces; and limitanei, lower-grade border troops.Jones (1964) 610 (See Late Roman army).
