Ottoman claim to Roman succession

After the conquest of Constantinople in 1453, the sultans of the Ottoman Empire laid claim to represent the legitimate Roman emperors. This claim was based on the right of conquest and mainly rested on possession of Constantinople, capital of the Byzantine (Eastern Roman) Empire for over a millennium. The sultans could also claim to be rulers of the Romans since they ruled over the former Byzantine populace, which continued to identify as such. Various titles were used by the sultans to stress their claim, including kayser-i rûm ("Caesar of Rome") and basileus (the Byzantine ruling title).

The early sultans after the conquest of Constantinople of the Classical Age—Mehmed II, Bayezid II, Selim I and Suleiman I—staunchly maintained that they were Roman emperors and went to great lengths to legitimize themselves as such. Constantinople was maintained as the imperial capital, Greek aristocrats (descendants of Byzantine nobility) were promoted to senior administrative positions, and architecture and culture experienced profound Byzantine influence. The claim of succession to the Roman Empire was also used to justify campaigns of conquest against Western Europe, including attempts to conquer Italy.

The Ottomans never formally dropped their claim to Roman imperial succession and never formally abandoned their Roman imperial titles, though the claim gradually faded and ceased to be stressed by the sultans. This development was a result of the Ottoman Empire increasingly claiming Islamic political legitimacy from the sixteenth century onwards, a result of Ottoman conquests in the Levant, Arabia, and North Africa having turned the empire from a multi-religious state to a state with a clear Muslim majority population. In turn, this necessitated a claim to legitimate political power rooted in Islamic rather than Roman tradition.