The Imperial Army (帝国陸軍 Teikoku Rikugun) is the main army used by the Empire. The Imperial Army is similar in appearance and structure of the real-world Roman Army of its mid Imperial period, being made up primarily of formations of heavy infantry armed with spears, swords, large rectangular shields, and utilizing Roman testudo formations in battles. Also present in the military are cavalry, archers, siege engines such a battering rams, ballistae, and trebuchets, and dragon riders. Auxiliary forces are provided by both human and goblin vassal and clientel states of the Empire.
While the Empire is very Roman-like, their technology level is particulary more late-medieval. For instance the Imperial cavalry, who are typically similar in appearance to medieval knights, clad in plate armor and armed with swords and lances. Other medieval weaponry used by the Empire include halberds and trebuchets.
Since all the events in Gate have taken place on land, there has been no direct contact with the Imperial Navy. A map of the Special Region depicts a Greco-Roman-style warship or trireme like in the classic ancient period, a mixed oar and sail powered vessel armed with a forward naval ram. This suggests the Empire or their vassal states possess some form of naval forces. It is later revealed that Imperial Navy is equivalent to the ancient Roman style warship in term of combat, which involves ramming ship into enemy ship at fast speed or firing rain of arrows from one ship to another ship.
Despite their inferior and primitive weaponry, they still pose some threats to the JSDF, especially in large numbers when conducting ambush. In the Imperial Civil War, they manage to inflict some damages to the JSDF through human wave tactics and ambushes. However, due to Zorzal's idiocy and lack of wise thinking, they often lose against the JSDF since they not fully adapt to JSDF weaponry and tactics based on the fact that they never incorporate firearms into the army. Therefore, they only manage to win against the JSDF through short term attrition with massive casualties until they are being utterly defeated by JSDF's superior weaponry.
Much like the Roman army, 80 soldiers or ten contubernium each consists of 8 soldiers will form a century lead by a Centurion. Six centuries together make up a cohort lead by Primus Pilus (The First Five) followed by his superior Camp Prefect who in charge of the daily operation in the camp; 5 tribuni augusticlavii and 1 tribunus latclavius who is also a future potential senator. Finally, ten cohorts will create the largest division of troops is referred to as a legion lead by the Legion Legatus (General) who are also the member of the Senate. Other divisions of the army are not known, and it is not clear how the size of an Imperial legion compares to that of a Roman legion in the Early-mid Imperial periode (3.000-6.000 man per Legion and 1.000-2.000 man auxillaries) or the late Antiquity (1.000 man per comitatensis (field army) or Limitanei (border guard army) with 500-1.000 man foederati (barbarian mercenaries) in both).Auxiliaries like Orcs, Goblin or Troll and orders of knights are separated like foederati barbarian mercenaries or buccellari (Knight-like, by roman generals paid heavy armoured and mounted mercenaries) in the late Antiquity.
All Auxiliaries members are non-Empire citizen and are often treated as meat shield and cannon fodder for the main Imperial force. Due to the racism against humanoid, these Auxiliaries members cannot gain citizenship like in the real-life Auxiliaries soldiers (an Auxiliaries Roman soldier can gain citizenship after 35 years of services).
In the Imperial Palace, there are the elite group of soldiers called Imperial Guard who are in charge of protecting the King, the royal family and the Senate. Despite their superior fighting power over normal soldier, they are still being outclassed by the Rose Order of Knight since Bozes and Beefeater can defeat several of them with ease.
Prisoner of war
The normal way of treating prisoners, for the Empire, usually involved dragging them behind a horse, and when the prisoners collapsed from exhaustion, they would be poked with spears or lashed with the flat of a blade, forcing them to rise and continue. Even if they did stand, however, they would still be brutalized with fists and feet. In this way, the prisoners would lose the will and strength to resist or flee, and it was also part of the process of breaking them before selling them as slaves.
Little is known about the pre-contact history of the Imperial Army, or indeed the Empire itself. It is known, however, that about 250 years prior to the events of Gate (mid-1700s Earth calender), the Imperial Army participated in a long and difficult conflict known as the Arctic War, presumably with some northern race or civilization. The contact presumably ended in an Imperial victory.
Before their failed invasion of Japan, the last major action the Imperial Army took part in was the conquest of the Warrior Bunny tribes under Zorzal El Caesar. This conflict was an unprovoked act of aggression that prompted by the need for slave labor in the Empire. The Empire was victorious, albeit with severe casualties. Zorzal ordered all of the Warrior Bunny tribes enslaved or slaughtered, and took their queen, Tyuule as his personal sex slave.
In 20xx, the Empire crossed the Gate into Japan, but was quickly defeated at the Battle of Ginza by the technologically superior Japan Self-Defense Forces. The JSDF followed up their victory at Ginza with an invasion of the Special Region.
First and Second Battle of Alnus Hill
After their defeat in Ginza, the empire has attempted to drive the JSDF back through the Gate, however they experienced a crushing defeat of the Imperial and Allied Army at the Second Battle of Alnus Hill, thanks to the far superior firepower of JSDF artillery, tanks, and machine guns. The battle resulted in the loss of over 60,000 Imperial soldiers, leading to a significant decline in Imperial military power and political influence.