Servant of the servants of God

"Servant of the servants of God" is one of the titles of the Pope and is used at the beginning of papal bulls.

History

Pope Gregory I, the first Pope to use this title extensively to refer to himself, deployed it as a lesson in humility for the archbishop of Constantinople John the Faster, who had been granted the traditional title "Ecumenical Patriarch"
by a Council convened in Constantinople in 587.
Gregory reportedly reacted negatively to the Patriarch's title, claiming that "whoever calls himself universal bishop, or desires this title, is, by his pride, the precursor to the Antichrist."