Conversation so far:
Was the critic Robert Hughes married?
The critic Robert Hughes met his first wife, Danne Emerson, in London in 1967
What year did the critic Robert Hughes and Danne Emmerson get married?
In 1967, the critic Robert Hughes married Danne Emerson.
Did the critic Robert Hughes and Danne Emerson have any children?
The critic Robert Hughes and Danne Emerson's son, Danton, was Hughes' only child.
What was the critic Robert Hughes and Danne Emerson son's occupation?
Danton Hughes was a sculptor.

Question: When did Robert and Danne get a divorce?
Self-contained rewrite: When did the critic Robert Hughes and Danne Emerson get a divorce?