Conversation so far:
When was George Orwell in Hampstead?
In the mid 1930s Orwell found himself working part-time in a bookshop in Hampstead, called Booklover’s Corner, situated where Pond Street and South End Road meet.
What did George Orwell do in Hampstead?
George Orwell was a part-time assistant in Booklovers' Corner, a second-hand bookshop in Hampstead
How long did George Orwell live in Hampstead?

Question: why did he leave
Self-contained rewrite: Why did George Orwell leave Hampstead?