To refresh or get a broad view of the period. Who knew who and worked with whom. They all knew each other and fought each other over colour, form, theory. From Picasso and the cubism's influence to the less known Metz movement, you get all the players, the time line and the world events that shape them all. It's an introduction nothing more. For me it was a refresher before diving into the more dense, 600 pages Avant-Gardes.