Governor SPOILERS

There is no mention of an extensive civil war attending the formation of the Empire in Path of the Fury, as there is of the League War, and the Wars with the Rish. Did Terrance Murphy, first of his house and of his name, succeed in transforming the Terran Federation into the Terran Empire without significant bloodshed?

I don't believe there will be much of a Civil War.

So far the Fed's most trusted military force is the Army. And the rule is that when the Navy controls the orbitals, the ground forces have to surrender

One of the FTLCs that joined Murphy had a loyal commander. Who was quickly dumped by a loyal to the Fringe commander. Who was apparently supported by the majority Fringe crew.

And from what we saw, the Heart World conscripted crews are particularly loyal to the government, either.

IMO, the 500 are going to have enough power to force Murphy to create the Empire, and then be shocked to discover that they have no support for resisting it once they've forced it to come into existence.

I expect that to finish up in the second book. Possible the rest of the 2nd book, and all of the 3rd, will be fighting the Rish.

IMAO

The 500 are making money selling Rish luxuries to other members of the 500

When it becomes clear to the rest of the populace that the government is refusing to admit Rish complicity in the murder or 6 billion humans, because they don't want to lose the Rish luxury trade, the government is going to quickly lose its legitimacy