Aleksandr Pavlovich vs Czar Alexander I

Aleksandr Pavlovich and Czar Alexander I both are nouns.

Word	Noun	Adjective	Verb	Adverb
Aleksandr Pavlovich	Yes	No	No	No
Czar Alexander I	Yes	No	No	No

As nouns, Aleksandr Pavlovich and Czar Alexander I are synonyms defined as:

Aleksandr Pavlovich and Czar Alexander I: the czar of Russia whose plans to liberalize the government of Russia were unrealized because of the wars with Napoleon (1777-1825)

Other synonyms of Aleksandr Pavlovich include Alexander I, Alexander I of Russia.

Aleksandr Pavlovich (noun)	Czar Alexander I (noun)
the czar of Russia whose plans to liberalize the government of Russia were unrealized because of the wars with Napoleon (1777-1825)	the czar of Russia whose plans to liberalize the government of Russia were unrealized because of the wars with Napoleon (1777-1825)