Alexander II vs Czar Alexander II

Alexander II and Czar Alexander II both are nouns.

Word	Noun	Adjective	Verb	Adverb
Alexander II	Yes	No	No	No
Czar Alexander II	Yes	No	No	No

As nouns, Alexander II and Czar Alexander II are synonyms defined as:

Alexander II and Czar Alexander II: the son of Nicholas I who, as czar of Russia, introduced reforms that included limited emancipation of the serfs (1818-1881)

Other synonyms of Alexander II include Alexander II of Russia, Alexander the Liberator.

Alexander II (noun)	Czar Alexander II (noun)
the son of Nicholas I who, as czar of Russia, introduced reforms that included limited emancipation of the serfs (1818-1881)	the son of Nicholas I who, as czar of Russia, introduced reforms that included limited emancipation of the serfs (1818-1881)