When I read the wonderful book Picasso’s War, I learned about the Rosengart family, who were one of Picasso’s dealers. Picasso was under contract with them to automatically sell them whatever he produced. What a great situation for an artist! So it was the Rosengarts (among others) who helped put Picasso on the annals of history.
The Rosengarts also represented Klee and others, and the dealers kept their favorite paintings and drawings, instead of selling all of them. Their wonderful collection is now housed in this perfect little museum in Lucerne.
Check out in this post, some of this remarkable collection.