Conversation so far:
What was Marc Chagall doing in France in 1923?
In 1923, Chagall left Moscow to return to France.
What was Marc Chagall looking to do once he returned to France in 1923?
after returning to Paris he again rediscovered the free expansion and fulfillment which were so essential to him“
What kind of pictures Marc Chagall was into or did?
With all his early works now lost, he began trying to paint from his memories of his earliest years in Vitebsk with sketches and oil paintings.
What else did Marc Chagall do during those years after trying to paint from his memories of his earliest years?
He formed a business relationship with French art dealer Ambroise Vollard.

Question: What did their business consist of?
Self-contained rewrite: What did Marc Chagall's business consist of?