: Justinian commissioned the Hagia Sophia , a feat of engineering that remained the world’s largest cathedral for nearly a millennium.
The empire’s origins lie in the restructuring of the Roman state. A History of Byzantium
: Facing a Crisis of the Third Century , Emperor Diocletian divided the Roman Empire into East and West to make it more governable. : Justinian commissioned the Hagia Sophia , a
: He codified Roman law into the Corpus Juris Civilis , but his reign was also marred by the devastating Plague of Justinian , which decimated the population. III. Survival and Transformation (610–1025 AD) : Justinian commissioned the Hagia Sophia