Complex sentence: Jean Schlumberger (1877-1968), a French writer, journalist and co-founder of the "Nouvelle Revue Française", a French literary journal, is best known as a writer of novels, plays and books of poetry.
Split into simpler sentences: Jean Schlumberger (1877-1968) was a French writer, journalist and co-founder of the "Nouvelle Revue Française", a French literary journal. He is best known as a writer of novels, plays and books of poetry.