Keep in mind that the name of these nations are translated from Japanese so the translation of names may be incorrect or differ from place to place. For more information, see Terminologies.
The Youjo Senki series has several nations present in the story, which are mostly located in Europe. 
Main Article: Empire
The Empire is the nation in which most of the story has taken place in so far, and it is the nation where our main character, Tanya Degurechaff, lives in. The Empire is noted for having a very strong military, and it is currently at war with several of its neighbouring countries.
Legadonia Entente Alliance レガドニア協商連合
Main article: Legadonia Entente Allaince
The Legadonia Entente Alliance is one of the Empire's enemy nations, and is located over the northern border, with the area of Norden being contested between the Entente Alliance and the Empire.
A long time before the events of Youjo Senki occur, the Empire and the Entente Alliance had an unofficial dispute over the drawing of the national border, and nowadays after garrisons from both nations misfired accidentally and firefights broke out because of some misunderstanding, alerting people to the tense situation here. June, 1923, Norden Incident occurred, which the Entente Alliance should take the blame for.
Border area of Norden is where Tanya Degurechaff officially fought for the first time and also where she awarded the Silver Wings Assault medal, the highest military decoration given by the Empire.
Francois Republic フランソワ共和国
Main article: Francois Republic
The Francois Republic is one of the Empire's enemy nations and borders the Empire to the west. They have the border and territorial disputes for a long time, and ever broke out several regional wars.
The Republic had launched a surprise attack while the Empire was focused on the war against the Legadonia Entente Alliance and had occupied part of the Empire's lands in the Rhine region.
In the Rhine battlefront, Tanya Degurechaff was registered in the databases of the Francois Republic and became the "Devil of Rhine"; there she was regarded, after reaching the 50th confirmed shooting down, as an Ace of Aces.
It was during Tanya's tenure here, as leader of Platoon 3 she met for the first time Viktoriya Ivanovna Serebryakov, who became her first subordinate.
United Kingdom/ Allied Kingdom(anime) 連合王国
Main article: United Kingdom
- This country's history status is similar to the British Empire in World War I. In order to prevent the birth of hegemonic nation in the continent, it helps the belligerents fighting against the Empire to achieve a balance in power. It has not yet a direct role (deployment of troops and such) in the continental conflict, thus it only gives supplies to the Republic currently.
Dacia Grand Duchy ダキア大公国
Main article: Dacia Grand Duchy
- This country's history status was "inspired" by the Kingdom of Romania in World War I. For the sake of taxing the Empire's internal mobilization strategy, it declared war on the Empire. As such, a third front was opened with hope they could draw Imperial units away from the Rhine battlefront, and then consequently force the Empire to hold peace talks. However, this proved deeply wrong, since Dakia had not developed yet any proper mage academy, and did not had any effective counter-air defence strategy, using infantry tactics typical of the previous century. Being useless against World War military tactics, these finally led to the destruction of the Invasion force three full-armed division (600,000 men) and of its military–industrial complex inside its capital. (Note: the anime nerfed Romania completely)
Ildoa Kingdom イルドア王国
Main article: Ildoa Kingdom
- This country's history status is similar to the Kingdom of Italy in World War I. Despite the Republic's exhortations for joining to the Allies, it formed an alliance with the Empire, maintaining its neutrality in the beginning of this war.
Rus' Union/ Russy Federation(anime) ルーシー連邦
Main article: Rus Union
- This country's history status is similar to the Soviet Union. Its former imperial government was the main ally of the Republic against the Empire, but the nation changed side after a revolution, which led to the birth of the new communist government and forced Republic to mainly rely on their alliance with Legadonia Entente Alliance. The new government signed a nonaggression pact and other treaties with the Empire, and kept its neutrality in the beginning of this war.
Unified States 合州国
Main article: Unified States
- This country's history status is similar to the United States in World War I. It is the creditor to most of the belligerents in this war. Its policy tended to keep its neutrality for the sake of commercial interests.
Akitsushima Empire 秋津洲皇国
Main article: Akitsushima Empire
- This country fought a war against the Rus' Union in the past. Border skirmishes still happen between Akitsushima and Rus'.
- This country is located in where Switzerland is in real life, and similarly maintained neutrality. Anson Sue's submachine gun was make by the Arnold-Smith Arsenal in Waldstätten.
- This country owns the entire Iberian Peninsula and has vast colonies in the Southern Continent as well. However, Hispania is too preoccupied with political strife to participate in diplomacy and hence maintained neutrality.
Turkmen Principalities トルクメーン諸公国
- This country or countries has a presence in the Southern Continent, which put them into conflict with Ildoa when the latter started its colonies there. Its or their location is unknown.
- This country consists of southern Balkans and Anatolia according to the maps in the anime, but has never been mentioned elsewhere. The maps of the LN and manga also shows an unlabeled country in the same area, although much smaller than the Magna Rumeli in the anime.
- ↑ https://ja.wikipedia.org/wiki/%E5%B9%BC%E5%A5%B3%E6%88%A6%E8%A8%98
- ↑ Deus lo vult - Chapter III The Watch/Guard On The Rhine
- ↑ "Akitsushima" is a poetic name for Japan.
- ↑ Plus Ultra - Chapter I: The Dacian War
- ↑ Dabit deus his quoque finem - Chapter II: Goodwill visit
- ↑ The Finest Hour - Chapter V: Internal affairs
- ↑ The Finest Hour - Chapter V: Internal affairs