Rome gained recognition from the “Christain empire” as supreme bishop through usurpation by a disgruntled aristocratic bastard usurper who was in contact with the popes & had the support of the green chariot team (proto mafia) named phocas. More below.

Before the Usurper Phocas treaty of papal primary recognizing Pope Boniface III & as the "Head of all the Churches" & "Universal Bishop” All 5 major patriarchs were equal.

Disputed councils & eastern emperors gave Constantinople that privilege as center of the Christain empire.

Phocas was a Thracian centurion who led a mutinous Balkan army to Constantinople in 602 while riots were stirred against Maurice.

Phocas had the backing & assistance of the green chariot (mafia) team.

This was a coup by Rome when the eastern empire was becoming a loose end.