Didn't support Merlin's Phoenix Empire thingy.
I assumed that it was something else since one of the two stated reasons for doing the Phoenix Empire thing was because he (the Duke) was being difficult (according to the official story).
How could he objecting to the Phoenix be a driving force behind the Phoenix? Do you see how it all turns into a loop?
Except for the changing from Republic to Monarchy-thing. Maybe it is that simple?
