Sergei Diaghilev vs Diaghilev

Sergei Diaghilev and Diaghilev both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sergei Diaghilev	Yes	No	No	No
Diaghilev	Yes	No	No	No

As nouns, Sergei Diaghilev and Diaghilev are synonyms defined as:

Sergei Diaghilev and Diaghilev: Russian ballet impresario who founded the Russian ballet and later introduced it to the West (1872-1929)

Other synonyms of Sergei Diaghilev include Sergei Pavlovich Diaghilev.

Sergei Diaghilev (noun)	Diaghilev (noun)
Russian ballet impresario who founded the Russian ballet and later introduced it to the West (1872-1929)	Russian ballet impresario who founded the Russian ballet and later introduced it to the West (1872-1929)