Complex sentence: Paul Rosenberg (29 December 1881--29 June 1959) was a French art dealer, renowned for representing Pablo Picasso, Georges Braque, and Henri Matisse.
Split into simpler sentences: Paul Rosenberg (29 December 1881--29 June 1959) was a French art dealer. He was renowned for representing Pablo Picasso, Georges Braque, and Henri Matisse.