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