This is a family tree of all the Eastern Roman Emperors who ruled in Constantinople. Most of the Eastern emperors were related in some form to their predecessors, sometimes by direct descent or by marriage. From the Doukid dynasty (1059) onwards all emperors are related to the same family.
Dynasty names are given in capitals so that they can be picked out from the interweaving trees. Junior co-emperors who never exercised real power are shown in a smaller font to distinguish them from the reigning emperor.
This is a simplified family tree centered solely around the Eastern Empire, for a fuller list that includes both Eastern and Western emperors, see Family tree of Roman emperors