After nearly three thousand years The Republic of Rome has finally adopted a standardized structure for their basic combat unit, which is the Century. A Century is made up of ten Contuberniums (Squads) and one Headquarters Vexillatio (Detachment). The line Contuberniums are made up of the vehicles/personnel needed to carry out the Century's mission. If the Century is a signals unit, the Line Contuberniums will be manned with Signals Personnel and equipment. Lorica (Armor) Centurys use Loricas. The Headquarters Vexillatio provides supply, maintenance, and battlefield recovery assets.
Ten Vehicles make up an armored Century. If the Century is a Mechanized Legionarius Century, the Infantry are organized into Contuberniums of ten men and assigned to one Papilio Armored Personnel Carrier to transport each Contubernium.
Combat Centuries are pure units and contain only the type of asset determined by the role assigned to it. Any heavy weapons support such as mortars is provided by an attached Auxilia of the proper type.
A Headquarters Vexillatio has four vehicles usually attached, a Legati Command APC, Aerarius Recovery Vehicle, a Vigiles Flak track, and a Mulus Hover supply vehicle. A Headquarters Century has four Contuberniums with 5 of each of the type of vehicles attached to a HQ Vexillatio, Legati, Aerarius, Vigiles, and Mulus. A Cohors and Legio Headquarters is assigned a variety of Centuries, these include an Administrative Century, A Command Century, an Intelligence Century, a Vigiles Century, a Mulus Century, and a Liaison Century, for coordinating activities with the Classis (Navy) and any attached Ground Support Air Auxilias.
The numbering system used to identify a unit is fairly standardized throughout the Republic. Some units, expecially the ones formed before the leap to the stars, have names as well as a unit number. Unit are identified by the designation of the Century, the Century's Maniple, or Turmae for the Ala, the Maniple's, or turmae's, Cohors, and then, finally, the Legio itself. For example; IV Century, VI Maniple, III Cohors, XXXV Mechanized Legio. or for a named unit; IV Century, VI maniple, III Cohors, Legio XXX Ulpia Victrix.
SPQR LEGIO ORGANIZATION
The basic unit is the Legio. Even though some of the Legios can trace their history back to the first Republic, you have to remember there is going to be some variations due to the modern complexity of warfare. But they all share the same basic structure.
A Roman legio consists of three Combat Cohorts, a Tormentum (Artillery) Auxilia, A Fabrum (Engineer) Auxilia, a Medical Auxilia, a Vigiles Aquilia (anti-aircraft) Auxilia, A Rationibus Castrensis (supply) Auxilia, and a Legio Headquarters vexillatio. The legio is commanded by either a Legati Legionis, Infantry or Marine, or a Praefectus Equitum for Armored Legios. A Tribunus Laticlavius is the Executive Officer and second in command of the Legio.
The striking arm of the Legio is its three Combat Cohorts. The First Cohort is always manned by the best troops assigned to the Legio, and is always the first to recieve any new equipment being deployed. The First Cohort consists of a Headquarters Century and five Combat Maniples. The other two Cohorts are the same, just the First is the prestige unit for the Legio. Cohorts are commanded by a Tribunus Laticlavius, and Maniples are commanded by a Tesserarius.
The Combat Cohorts will detach maniples for specific missions into temporary detachments of two to five maniples. Called the Adlectus Praetorii, Transferred Adjutant. Depending on the mission, the Legio's Legatus can assign it support units from the Tormentum - artillery -, signifer - signal -, Rationibus Castrensis - supply -, vigiles - military police -, or Fabrum - engineer - elements. A Legio has sufficient Headquarters Vexillatio's to form five additional Adlectus Praetorii. An Adlectus Praetorii is commanded by a Tribuni Angusticlavii.
The Tormentum Auxilia consists of 3 maniples each consisting of five Centuries of Ballistae and five Centuries of Martiobarbulus heavy tormenta and one Pila Century. The pila century is capable of launching satellites (primarily observation satellites) into planetary orbit. Tormenta Centuries are assigned to an Adlectus Praetorii as intact units and are never broken up. The Pila Century is always controlled directly by the Legio's Headquarters Vexillatio.
The Praefectus Vigilum Auxilia consists of 3 maniples each consisting of five Centuries of Praefectus Vigilum (Anti-Orbital), five Centuries of Vigiles Aquilia (A.D.) and five centuries of Pila A.T. Tormentum. The Vigiles's Centuries are assigned piecemeal to individual Adlectus Praetorii or to rear area defense.
The Rationibus Castrensis Auxilia controls the activities of the Legio's maintenance, supply, medical and other administrative units. These elements are normally assigned as needed to support the operations of the different Adlectus Praetorii.
The Signifer Maniple is responsible for all aspects of communications. They ensure that the Legio Headquarters are able to communicate with their far-flung Adlectus Praetorii, support units and higher Headquarters. Their mission includes the use and maintenance of communications satellites, though launching is the responsibility of the Pila Centuries. The Signifer Maniple is also responsible for signals intelligence (sig-int), signals security (sig-sec), and electronics countermeasures (ecm). Signifer Centuries are assigned to various Headquarters as needed.
The Fabrum Auxilia is responsible for the construction and maintenance of any permanent Legio facilities, clearing or emplacing obstacles, erecting barricades, and constructing fortifications. The Auxilia has three Bridging Centuries, three Construction Centuries, three Combat Engineer Centuries and three Combat Recovery Centuries. The Combat Engineer Centuries are assigned the Adlectus Praetorii as needed, while others are mainly used in rear area duties.
The Vigiles (MP) Maniple consists of ten line Centuries and functions as a rear area security force. It is also used to maintain military discipline within the Legio. The Vigiles Maniple is under the direct control of the Legati Legionis, and only rarely is it divided up to support Adlectus Praetorii operations.
Legio Support
Depending on its mission, a Legio can be assigned a Wing of supporting aircraft and/or a variable number of Auxilia units. An Auxilia - unlike organic Legio units - has four to six Maniples of specialized troops, such as penal infantry, military police, marine assault troops, or population control troops (riot police). An Auxilia is about the size of an Adlectus Praetorii. unlike organic Legio units, an Auxilia is assigned organic support troops. This allows the Auxilia to operate without additional support troops for a limited time. In contrast an Adlectus Praetorii depends completely on Legio support units for maintenance in the field.
Legio Designations
As of the end of the Arachnid war there exists 3,000 Legios, along with innumerable specialised Auxilia. The majority of the Republic's Legios are designated Ala, Legionarii, or Urbanae Legios. All follow the basic Legio structure, but deviate to some degree both in organization and type of Maniple.
Ala Legio
Ala Legios are one of the Republics frontline combat units. Their mission is to destroy all enemy forces they encounter. they are not expected to garrison a region, just to seize it.
An Ala Legio consists of one Heavy Armor Cohort, one Medium Armor Cohort and one Legionarii Cohort. The Heavy Cohort is always the First Cohort, and contains five Equities Turmae (Armored Bns) of heavy armor.
The Medium Cohort contains five Equites Turmae. The Legionarii Cohort contains five Legionarius Maniples.
Before the Siliconate war all vehicles in the legio were tracked. Once that war had begun it was discovered that the advantages of a ground effect vehicle were many levels above a tracked vehicle in mobile combat operations. After the war ended the republic began to design and implement G.E.V. mobility into the Legios. As of the Arachnid war all vehicles in the Ala Legio are equipped with G.E.V. drives. This allows the Legio to use strategic and tactical advantages of G.E.V. equipped armor to their fullest extent, because the Legio's logistical tail is as maneuverable as the combat elements.
The Ala Legio has tremendous offensive firepower available, but relatively few combat infantry. This situation is commonly remedied by assigning the Ala Legio an Auxilia of some type of infantry. Depending on the type of combat expected and the likelihood of opposition by the populace at large, an entire Legionarii or Urbanae Legio may be attached to support an Ala Legio.
Legionarii Legio
The Imperial High Command views Legionarii Legios as defensive troops whose mission is to hold the ground won by the Ala Legios.
A typical Legionarii Legio has one Medium Armor Cohort, and two Legionarii Cohorts.
All vehicles in a frontline Legionarii Legio use G.E.V. drives. The Supply and Tormentum Auxilias of Legionarii Legios assigned to rear areas use tracked and wheeled vehicles for transportation. This ties these second-line units to a relatively fixed logistical train, but the cost of raising and maintaining the second-line units is less. If a second-line Legionarii Legio is assigned to the front, its support and artillery vehicles are usually replaced with G.E.V.'s.
Auxilia are assigned to the Legionarii Legio as needed. typical Auxilia assignments include armor, air/space defense or construction units.
Urbanae Legios
Urbanae Legios are the most numerous Legios in the Republics military. A Urbanae Legio's primary mission is population control, over and above normal civilian police duties. Roman doctrine calls for one Urbanae Legio to be stationed on a planet per ten million inhabitants. While it is capable of fighting tenaciously against an invading Ala or Legionarii Legio, an Urbanae Legio's lack of mobility and the generally lower quality of its Legionnaires guarantees that it will be eventually defeated by G.E.V.-mounted troops.
A typical Urbanae Legio has one Medium Armor Cohort (the First Cohort), one Airmobile Cohort and one Vigiles Cohort. The Military Police Cohort contains one Vigiles Maniple, and three Riot Control Maniples. The Fabrum Auxilia only has three Centuries of construction troops, and the Tormentum Auxilia exchanges two Maniples of Armored Artillery for two Air Defense Maniples.
The Urbanae Legio is not equipped with any G.E.V.'s. All the Legio's vehicles are either wheeled or tracked. Urbanae Legios are practically immobile in comparison to conventional military units, but this TO&E keeps the costs low. However, The Imperial High Command recognizes the vulnerability of the Urbanae Legio's logistical bases and usually assigns two additional air defense Maniples to redress the balance somewhat. This support comes at the cost of two-thirds of their ground artillery support.
If guerilla activity is especially heavy the Urbanae Legio might be assigned a GEV or VTOL transport Auxilia, capable of simultaneously lifting three Legionarii Maniples along with their organic vehicles.