Chan Wei Lik wrote:

From: David Johnston

<snip>

To the author: When are you going to tell us how did the Imperial universe
diverged from ours? It's been 12 chapters already and we still don't know
about that one. It's quite interesting given that most asian empires were
not very expansionist. Maybe because they had China as a neighbour? One
which didn't expand much either.

Actually, the author dropped some hints in the early part of the story.  IIRC, 
it diverged when the British won the American Revolution.  I would like
more details though.