How did succession work in the Roman and Byzantine Empires?

The Roman and Byzantine empires lacked formal, written succession laws, meaning hereditary descent was customary rather than a strict constitutional rule. Accession often depended on a complex process involving the military, bureaucracy, adoption, or usurpation. Possession of the capital city, Constantinople, frequently validated a new ruler's claim, leading various subsequent states to claim the imperial legacy.

What we know

• The Byzantine Empire lacked formal succession laws, and hereditary succession functioned as a customary tradition rather than an inviolable constitutional rule. [4, 5]
• Succession through adoption, illegitimate descent, or outright usurpation was not considered illegal in the Byzantine system. [5]
• The rightful ruler was often considered to be whoever managed to gain and hold possession of Constantinople at any given time. [5]
• Following the fall of Constantinople in 1453, both the Ottoman sultans and the Russian Empire claimed rightful succession to the Roman and Byzantine legacy. [2, 3, 5]

Still open

• The degree to which Christian populations within the Ottoman Empire viewed the sultan as a seamless continuation versus a successor heir remains subject to varying historical perspectives.

Where to go next

• what caused itWhat was the Ottoman claim to Roman succession?
• compared withHow did the Byzantine Empire differ from Western Europe?
• how we knowWho were the Byzantine emperors?
• whenWhat happened after the fall of Constantinople?
• the bigger pictureHow did European powers view the legacy of Rome?
• an unexpected connectionWhy did Ottoman sultans use Roman imperial titles?Ottoman rulers adopted the title Caesar of Rome and maintained Byzantine administrative structures because they claimed direct political continuity through the right of conquest after 1453.

Sources

• [1]succession of the Roman Empire (Wikidata Q96590840) · CC0 1.0
• [2]Succession of the Roman Empire · CC BY-SA 4.0
• [3]Ottoman claim to Roman succession · CC BY-SA 4.0
• [4]List of Byzantine emperors · CC BY-SA 4.0
• [5]Succession to the Byzantine Empire · CC BY-SA 4.0