Catherine vs Catherine II

Catherine and Catherine II both are nouns.

Word	Noun	Adjective	Verb	Adverb
Catherine	Yes	No	No	No
Catherine II	Yes	No	No	No

As nouns, Catherine and Catherine II are synonyms defined as:

Catherine and Catherine II: empress of Russia who greatly increased the territory of the empire (1729-1796)

Other synonyms of Catherine include Catherine the Great.

Catherine (noun)	Catherine II (noun)
empress of Russia who greatly increased the territory of the empire (1729-1796)	empress of Russia who greatly increased the territory of the empire (1729-1796)
first wife of Henry VIII; Henry VIII's divorce from her was the initial step of the Reformation in England (1485-1536)