Conversation so far:
When did Le Corbusier start painting?
1918
What did Le Corbusier do between 1918-1922?
Le Corbusier did nothing but concentrate on Purist theory and painting.
What is the name of Le Corbusiers cousin?
Pierre Jeanneret
What kind of architectures did Pierre Jeanneret and Le Corbusier design?
Several different single-family house models using modern industrial methods and materials.

Question: what was cubism?
Self-contained rewrite: what was cubism?