527    Byzantine Emperor Justin I names his nephew Justinian I as co-ruler and successor to the throne.

527    Justinian I becomes the sole ruler of the Byzantine Empire.

529    First draft of the ''Corpus Juris Civilis'' (a fundamental work in jurisprudence) is issued by Eastern Roman Emperor Justinian I.

558    In Constantinople, the dome of the Hagia Sophia collapses. Justinian I immediately orders that the dome be rebuilt.