Principality of Dacia

The  Grand Duchy of Dakia, also called Dacia in certain versions as a direct reference to the Latin name that was given to ancient Romania/Bessarabia. According to Tanya's knowledge, Dakia is a minor state that had yet to have a solid foundation.

It is a nation that was behind the times in terms of military prowess. They attempted to attack the Empire without any air support, but their vanguard force ended up annihilated by Tanya Degurechaff's flight wing.

Dakian War ended shortly as Imperial air-force and Tanya's wing routed out Dakian force with with unprecedented odd of 70,000 against 300,000. Later on Dakia is mentioned to be wiped off the map in six week and by the time Orse Fryord fell under Empire's control, Empire already had full control of Dakia and smoothly setting up their administration.

International Relations
There isn't much known about their diplomatic relation with other country, but Tanya suspect their declaration of war is most likely incited by either Republic or other nations that would be benefited if Empire have to fight tri-pronged war.

Francois Republic (フランソワ共和国) Their Carbellius weapon factory is mentioned as a facility sponsored by Republic. So just like Legadonia, Dakia received support from allies for their military to an extent.

Military Strength
The military of Grand Duchy of Dakia is on the verge of late-19th century strategy and machinery. As their infantry is still moving with lines and armed with conventional turn-bolt rifle. Devoid of any form of air support and anti-air weapon, Dakian army is easily wiped out by assault from the sky.

Trivia

 * On the maps that show up in the background of the anime, the country's name shows up as "Grosherzogtum Dacia" in a highly stylized font.
 * In anime, the weapon making scene inside their weapon factory shows a worker making artillery shell.