285-305: Diocletian
293: Diocletian institutes tetrarchy
305-311: Galerius
311-324 : Licinius
324-337 : Constantine
337-361: Constantius II
361-363: Julian
363-364: Jovian
364-378: Valens
379-395: Theodosius I
395-408: Arcadius
408-450: Theodosius II
438: Codex Theodosianus promulgated
450-457: Marcian
457-474: Leo I
474: Leo II
474-491: Zeno
491-518: Anastasius I
518-527: Justin I
527-565: Justinian I
529: Codex Justinianus
534: Second edition of Codex
565-578 : Justin II
578-582 : Tiberius II Constantine
582-602: Maurice
602-510: Phocas
610-641: Heraclius
636: Battle of Yarmuk