Imperial Militia

The Imperial Militia was the reserve branch of the, providing the second and third lines of defense of the and directly subordinated to the. All  citizens of the  between the ages of 21 and 43 s were required to register with the Imperial Militia. They were then divided into four categories, including those that had already served in the Army or (Class I), those that have not served but are fit for combat duty (Class II), those that for medical or other reasons were not considered to be eligible to serve as combatants but still capable of bearing arms (Class III), and those that would be traditionally barred from military service of any kind for various reasons (Class VI). During times of crisis, the Imperial High Command was able to mobilize units of the Militia to assist the active duty troops, which were organized based on s.

The possessed its own equivalent, known as the Imperial Naval Auxiliary, although it functioned differently than the Militia.

Personnel
As the Imperial Militia's ranks were drawn from all Human male Imperial citizens between the ages of 21 and 43 standard years, its potential members were all organized into four categories based on their eligibility for service. During times of crisis, the Militia's personnel would be mobilized based on categories and on the urgency of the situation, with Class I militiamen being called up first.
 * Class I — Citizens that had previously served in the Imperial Ground Forces, Intelligence, or COMPNOR, and thus had both military training and experience already. Those that had been veterans of the Republic Military during the Clone Wars or earlier were considered to form a subdivision of Class I, regarded as slightly less capable than those that had undergone service in the Imperial forces.
 * Class II — Citizens that had not served in any of the above organizations and had no military training or experience, but were physically fit for service.
 * Class III — Citizens that were ineligible for combat service but were still capable of bearing arms, such as those with dependent family members or minor medical conditions.
 * Class IV — Citizens that were usually ineligible for military service of any sort, such as convicted criminals and those with major physical problems.

From among the above personnel, when large numbers were mobilized, Class I typically formed the officer corps and NCOs of Militia units, while Class II and and under were considered to be enlisted troops. However, in practice, when regional formations of the Imperial Militia underwent full-scale mobilization, there were frequent shortages of officers and non-commissioned officers due to the much smaller number of Class I militiamen relative to the other classes.

Field structure
Similarly to the regular Imperial Military, the Militia's organization was based on sectors. But unlike regular units they answered directly to the High Command on rather than the local. The highest level was a Sector Guard, which was an administrative formation that managed the Militia's available strength in one entire sector. The headquarters of a Sector Guard was responsible for working with the civilian authorities to oversee and execute a mobilization, then managing its units as the situation demanded. The highest level below that was a corps, managing the mobilization and units within a single. The biggest operational unit that actually functioned in the field was a regiment, which consisted of four battalions. A battalion was organized based on planetary localities, while the company formed the lowest unit below that.