Who was Justinian?
Justinian I (r. 527–565 CE) was the greatest Byzantine emperor, whose ambitious reign produced the Corpus Juris Civilis (which codified Roman law), the Hagia Sophia (the world's largest cathedral for nearly 1,000 years), and military campaigns that briefly reconquered much of the former Western Roman Empire.
Justinian I, who ruled the Byzantine Empire from 527 to 565 CE, was arguably the most ambitious and consequential emperor in Byzantine history. His reign represented the last great attempt to reunify the Roman Empire and produced achievements in law, architecture, and military conquest that shaped Western civilization for centuries.
Justinian's most enduring legacy was the Corpus Juris Civilis — the 'Body of Civil Law.' This massive project systematized a millennium of Roman legal precedent into a coherent code, including the Digest (a compendium of legal opinions), the Institutes (a textbook for law students), and the Codex (imperial laws). When European legal education revived in the 11th century, Justinian's code became the foundation of civil law traditions across the continent — a legal heritage that remains influential today.
The Hagia Sophia, completed in 537, was Justinian's architectural masterpiece. Its massive dome — 31 meters in diameter, appearing to float on a ring of windows — was an engineering marvel that remained the world's largest cathedral for nearly a thousand years. Justinian reportedly declared upon its completion: 'Solomon, I have outdone thee.'
Militarily, Justinian's generals (particularly the brilliant Belisarius) reconquered North Africa from the Vandals, Italy from the Ostrogoths, and parts of Spain. But these campaigns overstretched the empire's resources. The Plague of Justinian (541–542), one of history's deadliest pandemics, further weakened the fiscal and demographic base. His wife Theodora, a former actress of humble origin, was a formidable political partner whose courage during the Nika Riots of 532 may have saved his throne and his life.