Pope Gregory I vs Gregory the Great

Pope Gregory I and Gregory the Great both are nouns.

Word	Noun	Adjective	Verb	Adverb
Pope Gregory I	Yes	No	No	No
Gregory the Great	Yes	No	No	No

As nouns, Pope Gregory I and Gregory the Great are synonyms defined as:

Pope Gregory I and Gregory the Great: (Roman Catholic Church) an Italian pope distinguished for his spiritual and temporal leadership; a saint and Doctor of the Church (540?-604)

Other synonyms of Pope Gregory I include Gregory, Gregory I, Saint Gregory I, St. Gregory I.

Pope Gregory I (noun)	Gregory the Great (noun)
(Roman Catholic Church) an Italian pope distinguished for his spiritual and temporal leadership; a saint and Doctor of the Church (540?-604)	(Roman Catholic Church) an Italian pope distinguished for his spiritual and temporal leadership; a saint and Doctor of the Church (540?-604)