On the evening of the 5th of May, 1944 a vessel of the Nazi Navy approached the Imperial Waters and laid out an ultimatum to the people of the Empire. They were to accept the rule of Der Führer or be subjugated through war.
Seeing as the Navy of the Empire was not one to be a pushover to anyone, including an imperialistic warmongering nation such as Germany was at the time, three battleships left port at the main Naval Facility and several other smaller cruisers and destroyers left from some of the other smaller Naval Bases.
They met the Nazi fleet in the open water and ordered them to turn around. They were bet with retaliatory fire from the Nazi Fleet, striking several Imperial Ships and causing damage to them. With that, all the main guns from every single ship of the fleet turned it's attention to the Nazi command ship and opened fire, obliterating it in an instant and forcing the enemy fleet to retreat.
Once again, the Empire maintained that it was a force to not be trifled with and that they would not take part in any war that didn't involve them.