The cathedral with the highest nave (ie height of ceiling in the main worship area) is the Hagia Sophia. Its nave is ~7.5m/25ft higher than any other cathedral. Although it still stands, it is technically not a church anymore. The Romans took it for a while and then the Turks. It had been a museum and last year became a mosque again. https://en.wikipedia.org/wiki/Hagia_Sophia
The Romans took it for a while Do you mean the conquest of the 4th crusade? Those people weren't romans, arguably nobody was by the 13th century - perhaps if anyone, the locals had a better claim to it than the conquerors.
If you go by the criterion of (primary) self-identification there were Romans until the 1800s at least. By unbroken institutional continuity with the bureaucracy of Empire you can argue over whether it ended in 1453 or 1922.