The papal coronation of Frederick III was the last such event in the city’s history.
The last imperial coronation in the history of Rome was held on this date in 1452. Pope Nicholas V crowned Frederick III of Habsburg as Holy Roman Emperor. The coronation was held in Rome because it had a symbolic meaning – the Holy Roman Empire was seen as a continuation of the Roman Empire of classical antiquity, first revived by Emperor Charlemagne, who was crowned in Rome on Christmas Day 800.
The Habsburg rulers who came after Frederick III no longer came to Rome to be crowned, but simply automatically took the imperial title (the only exception was Frederick’s great-grandson Charles V, who was crowned by the pope, but in Bologna rather than Rome).
Just one year after the coronation, Constantinople fell to the Ottoman Turks, which ended the tradition of crowning the Byzantine emperor, which had lasted since the time of the Eastern Roman Empire. Therefore, the tradition of imperial coronations in both Rome and Constantinople ended at roughly the same time.