The Terran Empire (Parallel Universe)

In one parallel universe, earth is the control center for the Terran Empire, which seeks the conquest of all other worlds possible. It is under the reign of Emperor Heinz Doofenshmirtz, who has all children put in his schools to be indoctrinated in his evil ways. While this life can be brutal, many people emerge strong and undaunted by danger, even willing to die for the sake of honor. Its insignia is a black and yellow globe with a silver dagger through it to indicate the idea of conquest and aggression.

Foundation
While it is unclear how it was founded, Dr. Heinz Doofenshmirtz was able to somehow seize control first of the Tri-State Area, and then later the rest of the world in a short matter of time. According to Phineas Flynn of this universe, it was the combination of Doofenshmirtz's evil and the technical genius of Phineas and Ferb that made the Terran Empire what it was. While the exact time it was founded is unknown, it can be theorized that Phineas and Ferb of this universe had something to do with it since their very early years.

ISS Phineas
The flagship of the Terran Empire is the Flynn Class ISS Phineas (Registry#: PF-01), named after Phineas Flynn, a crucial part of the foundation of this empire. It is similar to the USS Phineas (also PF-01) of the Prime Universe, but it has more weapons and weapons arrays. It is led by Phineas Flynn himself, who is the Navy's fleet admiral (ranked as General) and whose friends are fellow shipmates and officers.

Other Naval Vessels
Nothing much is mentioned about the fleet in the story The Terran Empire (written by Tiberius64/Klingon64), but there was mentioned the existance of larger battle dreadnoughts that were devastated in the battle with the Prime Universe Phineas and Ferb. There are also apparently many other ships similar to the ISS Phineas in the fleet (Flynn Class starships) mentioned.