Pope Gregory told the Archbishop of Constantinople “that anyone who calls himself universal bishop is the precursor of anti-Christ.”
Peace be with you!
It was either John IV or John VI (I believe John IV) who called himself “eccumenical Patriarch” which is still used by the Patriarch of Constantinople today. The pope himself has never used that title, though out of respect others have referred to him as such (or something similar). If I remember correctly, Gregory and John ended up excommunicating each other, but it was later lifted by both churches.
**Very interesting, thanks RyanL. **