Commonwealth

Allied Kingdom (連合王国?) is a small nation with more than forty colonies in the alternate world.

International Relations
Unified States (合州国) - Due to lack of personnels, Allied Kingdom signed up an agreement to US to share knowledge, technology and volunteers to tear apart the Empire army.

Francois Republic (フランソワ共和国) - They signed a pact where Allied Kingdom will provide intel about the military and economic data of the Empire. Lending resources and provide ship cover in English Channel.

Commonwealth Nations - The nation needs a lot of manpower. They thought a good idea of using their former colonies to give aid and replenish their ranks.

Army
The Allied Kingdom has a third level of advanced military with limited trained soldiers. However, they can only use guerrilla tactics and used some camouflage to hid themselves. They are still no more much to the Empire's forces.

Navy
They have large amount of heavy and long-ranged battleships. They have the more advanced and powerful mechanized ships than the Empire.

Airforce
They have maximum air power and resistance and advanced long-ranged fighter planes. All of their pilots are elite and highly-trained personnel. Therefore, they put a lot of effort to maintain the air superiority in the sky. They are one of the strongest in air superiority.

Spy System
Allied Kingdom is one of the few countries who used knowledge, deception and gathering information about the enemies.

Trivia

 * On the maps that show up in the background of the anime, the country's name shows up as "Commonwealth" in a highly stylized font.