Military action
Avalon, the speaker of the house of lords, and De Ro supporter, removes the centers of power within the government. The ruling queen is killed after calling him in for a meeting. The rest of the capitol is calmed via magic as the Coup is completed.
The coup is the first step to putting General De Ro on the throne. The Empire was still operating as a small kingdom and was struggling to rule the vast amount of land due to squabbling nobles, who been given more power then they had right to hold. Too many hereditary titles were passed on rather then earned, some were even simply bought. Avalon following order from De Ro led the coup while De Ro used the Gnoll assault to rally troops from the countryside to his banner. These men were surplus to his core regiments and were less about filling his army as about depleting the army of the nobles that might try to rise against the new age. This was the age of the true empire, and he would lead them as their emperor.