Star League Defense Force
The Star League Defense Force (SLDF) was the principal military force defending the Star League, a conglomeration of star systems within roughly 500 light years of Terra. At its height the SLDF was the largest military force known to man, composed of over 100 million soldiers organized into 486 divisions. The Star League Defense Force left the Inner Sphere after fighting the Amaris Civil War, when Stefan Amaris overthrew the ruling First Lord of the Star League, Richard Cameron. After a long series of bloody battles throughout the Star League, Commanding General Aleksandr Kerensky ended the coup with the liberation of Terra and the execution of Amaris. However when no new First Lord could be agreed upon by the Great Houses the Star League was dissolved. Kerensky then led the surviving 113 divisions out beyond the Inner Sphere in Operation Exodus, hoping to save the essence of the League from the internecine violence that was to come. The SLDF would return 300 years later as the Clans, a technologically superior military that invaded the Inner Sphere in 3049.
 Organization and Combat Doctrines
At the birth of the Star League, the SLDF was comprised of ~270 regiments of ground forces (conventional armor, infantry and BattleMechs), as well as a fleet of greater than 500 capital vessels. At the outset of the Reunification War the SLDF was divided into 10 Corps. Each Corp was named based on its theater of operations and recruitment:
- First Terran Corps
- Second Rigilian Corps
- Third Altairian Corps
- Fourth Fomalhaut Corps
- Fifth Sirian Corps
- Sixth Astan Corps
- Seventh Procyon Corps
- First Reserve Corps
- Second Reserve Corps
- Star Guard Corps
By 2764, the SLDF had over 15,000 regiments and just as many WarShips, JumpShips and DropShips. This force was organized into 125 BattleMech divisions, 200 mechanized infantry divisions, 75 jump infantry divisions, and 50 infantry divisions, with the rest fighting as independent regiments. These formations were further combined into 20 armies divided between several military regions.
|Free Worlds League|
Though the composition of each of the Corps/Armies differed, a general rule of organization was maintained though all levels:
- An Army Group consisted of all the Armies assigned to one of the ten military regions. Those assigned to one of the member states were further divided into three districts and bore the name of the state's ruling family, i.e. Army Group Marik.
- An Army consisted of 3-4 Corps. Each of the three districts within each member state's military region was assigned its own Army.
- A Corps consisted of 1-3 BattleMech Divisions, 2-7 Infantry Divisions, several Independent Regiments, as well as its own WarShips and transports. Each Corps was usually assigned 30 worlds to protect, though that number could go as high as 100.
- A Division consisted of 3 Brigades, reserves, support units and an ASF Wing, although some had one more or less Brigade. The Division was the heart of the SLDF, usually charged with protecting a group of star systems within one jump radius, or one important system or planet. Divisions were usually classified as one of the following:
- BattleMech Divisions consisted of 2 BattleMech Brigades and 1 Mechanized Infantry Brigade. These units were primarily considered for offensive operations.
- Mechanized Infantry Divisions consisted of 2 Mechanized Infantry Brigades and 1 BattleMech Brigade. It was the most numerous type of unit and could participate in offensive and defensive operations, although the latter was their more usual function
- Infantry Divisions consisted of 2 Grunt infantry Brigades and a 1 light BattleMech Brigade. They were usually assigned to terrain hazardous to mechanized forces, such as cities and mountains.
- Jump Infantry Divisions consisted of 2 Jump Infantry Brigades and 1 BattleMech Brigade, as well as an additional Wing. Jump Infantry were primarily used for quick-strike missions requiring speed and surprise.
- A Brigade consisted of 3 Regiments, and were also sometimes known as Regimental Combat Teams, especially when composed of Light Horse regiments. While 3 regiments was the ideal, this number varied throughout the history of the SLDF.
- A Regiment consisted of 3 Battalions and was classified as one of the following:
- A BattleMech Regiment was typically organized as a Line Regiment, further classified as either Heavy Assault, Battle, or Striker depending on the role and weight class of their machines. Independent BattleMech Regiments were designed to operate on their own or with an infantry division against enemies too small to justify sending an entire 'Mech division. Therefore they also included non-'Mech components such companies of Jump Infantry or fighter squadrons. They were classified as Light Horse, Hussar or Dragoon depending on the role and weight class of their machines.
- Cavalry, Armored, Aerospace and Naval (CAAN) Regiments were Marine Corps units designed to operate on watery worlds, and so included blue water combat vehicles as well as 'Mechs, hovercraft and fighters.
- Armored Regiments were classified as either Heavy, Medium, or Light, as well as Wheeled or Hover. Armored Regiments always consisted of just one type of tank and were usually attached to divisions for anti-'Mech or assigned garrison duties.
- Artillery Regiments had no separate classification, though some included AirMobile Batteries with their own air transport. These regiments were typically attached to divisions, although some operated as independent regiments.
- Infantry Regiments were organized as Mechanized, Grunt, Jump or Marine units.
- A Battalion consisted of 3 Companies, also know as Batteries if made up of artillery units. Some BattleMech Battalions consisted of the same type of 'Mech, which helped greatly in reducing repair and maintenance problems. Occasionally, an artillery battalion would be attached to a 'Mech or armored regiment for additional fire support.
- A Company consisted of 3 Lances or Platoons if made up of infantry. BattleMech companies were almost always of the same type of 'Mech, though occasionally mixed companies were formed if it members had worked together through one of the Academies but qualified for different designs. The latter were assigned to Independent Regiments.
 Combat Role
Ground units of the SLDF were classified and equipped depending upon role.
- Heavy Assault BattleMech regiments consisted of mainly heavy-to-assault weight BattleMechs and a fourth company of artillery. The main assault force of the SLDF, most corps possessed at least a single Heavy Assault regiment.
- Battle BattleMech regiments were the core of most BattleMech brigades, consisting of medium-to-heavy weight 'Mechs.
- Striker BattleMech regiments were reconnaissance and breakthrough formations. Composed of light-to-medium weight 'Mechs, they also included a Recon company of Land Air 'Mechs, and usually had pairs of ASF assigned for their use.
- Dragoon BattleMech regiments were composed of heavy-to-assault weight 'Mechs, tanks and hovercraft, their primary purpose being to fight against well-equipped enemies.
- Hussar BattleMech regiments were the most common of the Independent regiments, composed of medium-to-heavy 'Mechs, tanks and hovercraft.
- Light Horse BattleMech regiments were primarily reconnaissance units, often the first one dropped onto a world to discover the enemy's strengths. Emphasizing light-to-medium weight 'Mechs and vehicles, at least two companies used dedicated information-gathering units like Ostscouts.
- Royal regiments were nearly identical to Regular regiments, with two exceptions. Royal regiments consisted entirely of soldiers of Terran Hegemony birth. Further, Royal regiments are the initial beneficiaries of BattleTechnology innovations - all Royal regiments were equipped with the ultimate in weapons development. Royal regiments served as the backbone of which each military region's force was built around.
A list of SLDF commands is available.
 Military Regions
General Shandra Noruff-Cameron, the SLDF's first Commanding General, divided the member states into six Military Regions for organizational purposes. The SLDF stationed an Army Group in the Capellan Confederation Military Region, Draconis Combine Military Region, Federated Suns Military Region, Free Worlds League Military Region, Lyran Commonwealth Military Region and Terran Military Region. The Periphery Military Region oversaw the Periphery nations as a whole, though eventually each Periphery nation was assigned its own military region.
 Commanding Generals
|Commanding Generals of the SLDF 2571-2801|
|Shandra Noruff||2571 - 2575||General|
|Carlos Dangmar Lee||2575 - 2597||General|
|Nicholas Kinnol||2597 - 2646||General|
|Killian Squarn-Turk||2646 - 2680||General|
|David Peterson||2680 - 2707||Admiral|
|Ikolor Fredasa||2707 - 2729||General|
|Rebecca Fetladral||2729 - 2738||General|
|Aleksandr Kerensky||2738 - 2801||General|
 Military Departments
The SLDF was organized into 15 different departments, or commands, each in charge of different aspects of organizing and managing the Star League's military forces. As it was the largest military organization in the history of humanity, each command faced unique challenges unlike their counterparts in the House armies. However, superior training and heavy reliance on computer technology allowed them to fulfill this role with as little as a third of the number of personnel required to run House military departments.
 Operational Commands
 High Command
High Command was responsible for control of the entire SLDF and presided over by the Commanding General or Admiral. When not in the field aboard a heavily modified battlecruiser, the Command's headquarters was the Citadel located next to the Court of the Star League. The Citadel was strong enough to survive an ASF ramming attack with insignificant damage and protected by a garrison of fighters and 'Mechs.
 Regular Army Command
This Command was in charge of all ground forces, and was further divided into eight Sub-Commands: BattleMech, Armored, Trooper, Fighter, Artillery, Engineering, Resupply, and Planning and Strategy.
This Command was in charge of all space forces, and was further divided into six Sub-Commands: WarShip, DropShip, Naval AeroSpace, Transport, Marine Corps, and Planning and Strategy.
 Royal Command
Formerly the High Command of the Hegemony Armed Forces, the Royal Command had two roles. The first was overseeing any issues or conflicts regarding Royal units within the army. The second, and less well-known role, was to act as a "shadow" High Command, issuing secret orders for Royal units to carry out.
 Special Forces Command
Special Forces Command held responsibility over all special units of the SLDF. This included the Special Armed Services, an elite anti-terrorism organization with over 100 battalion-sized formations, also known as the Blackhearts because of the calling card they left behind on their victims' bodies. The Blackhearts also made use of advanced Nighthawk power armor.
 Support Commands
 Intelligence Command
This Command was given the duty of gathering and analyzing military intelligence. From human agents to remote asteroid listening posts gathering even the most minute detail, Intelligence Command maintained a fleet of disguised JumpShips to gather whatever facts were collected by these sources and deliver them to the relevant Intelligence Section for analysis.
 Member-State Liaison Command
Member-State Liaison Command served two different functions. The first was maintaining good relations between the SLDF and the Great Houses, with liaison officers stationed assigned to many bases located within member state territory. The second, and arguably more important, was the integration of new recruits from member states into the SLDF, ensuring they thought of themselves from then on as a citizen of the Star League, rather than of House Steiner or House Kurita.
 Reserve Command
Reserve Command was responsible for maintaining reservist formations and their supplies, as well as supervising garrison units on Hegemony worlds.
 Judge Advocate General Command
Charged with administering the SLDF's code of conduct, the Judge Advocate General Command was also in charge of worlds under martial law or rebellion. Military governors would remain in command of worlds until the situation had calmed enough to assign civilian administrators to take over.
 Administrative Command
In charge of the upper echelons of the SLDF bureaucracy, this Command had the responsibility of gathering and organizing records from all other Commands. It also ran many of the SLDF's military academies and boot camps.
 Medical Command
Medical Command was charged with the medical treatment and care of all SLDF soldiers. It maintained a fleet of medical vehicles, spacecraft and orbital stations, and had access to the most advanced medical technology in the Inner Sphere.
 Logistical Commands
 Replacement-Deployment Command
The Replacement-Deployment Command held the responsibility of ensuring all units were at full strength. They were charged with transporting recruits to their newest assignment, as well as transporting the retired, wounded or dead back home.
 Quartermaster Command
The Quartermaster Command was charged with the shipping of supplies and policing of military contractors to ensure full compliance with the law. This Command, in conjunction with the civilian Department of Economic Relations, also monitored the over 300 major and hundreds of smaller weapons manufacturers within the Star League. If a firm was found to have broken the law, such as sharing advanced technology with another member state, either organization had the right to seize control of the company.
 Transport Command
Given the responsibility of organizing, regulating and tracking the transportation of men and material across the stars, Transport Command relied heavily on intricate timetables, constantly updated and coordinated through computer systems, to maintain quick and efficient delivery.
 Communications Command
 Military Installations
The SLDF had thousands of military bases and supply depots spread throughout known space; each inhabited world was home to at least one of these installations. Of special importance were those installations built along three defensive rings designed to protect Terra. The first, known as the Home Circle, was built along the border of the Terran Hegemony. The second was built 250 light years from Terran, while the third was built 500 light years from Terran, along the border between the Inner Sphere and the Periphery. Bases along the third ring were the largest and best defended, and more evenly distributed, and most major bases along the defensive rings were home to divisions or major fleets.
Besides the well-known installations, hundreds, potentially thousands, of secret bases were also constructed. SLDF engineers went to great lengths to construct these hidden bases: leveling mountains, draining lakes, building islands in the middle of oceans, and camouflaging their work when construction was complete. Such was their skill that many of these installations have yet to be found, and while most were emptied prior to Operation Exodus some still contain examples of lostech.
The most common type of military installations, Forts were designed to support the soldiers and families of a single regiment. Complete with housing, communication facilities, repair bays and a spaceport, the amount and type of defensive fortifications would depend upon the hostility of its host world.
Reserved for important or rebellious worlds, Castles were built into mountainsides or beneath meters of concrete and included multiple secret tunnels.
 Castle Brian
The most heavily defended of military installations, Castles Brian were first built along the Terran Hegemony's borders with its neighboring realms. Able to hold two brigades, the only sure way to eliminate one quickly was through heavy nuclear or orbital bombardment.
 Outpost Castle
 Port Castle
Another variation of the Castles Brian, Port Castles included a spaceport built into the facility, allowing for relief during sieges. Because the spaceport presented a vulnerable spot in its defenses, few Port Castles were built.
A smaller version of the Castle Brian, only able to hold a single regiment. Some Castles Brian included several Mini-Castles to act as a first line of defense.
 Supply Depot
The size and nature of a Supply Depot depended greatly upon the world it was built. On hostile worlds, most depots were built in secret or as part of a Fort or Castle.
Over 500 Naval Bases serviced the SLDF, each orbital facility including shipyards, moorings, and housing. Protection was provided for by an ASF wing and two destroyers, although during the final decades that force increased to include a cruiser.
 Military Academies
Of the more than 200 accredited military academies within the Star League, over 100 of them were located on Terra. Of the rest, all but three were located within the Terran Hegemony: Sanglamore Academy, The Nagelring, and Albion Military Academy. The lack of any other foreign academies was due in part to tensions between the Star League and its member states.
 Terran Academies
The Sandhurst Royal Military Academy in Berkshire, England, was considered one of the three foremost military academies known as the War Triad. This was in part because Michael Cameron, 2nd Director-General of the Hegemony, graduated from Sandhurst. Other notable Terran academies include, but are not limited to, West Point Military Academy, Malinovsky BattleMech and Tank Academy of Russia, Kreig Universitat of Germany, Frunze Military Academy, Annapolis Naval Academy, Kure Naval Academy of Japan, and Saint Cyr Military Academy of France.
In addition, Intelligence Command administered their own academies on Terra: the Riley Intelligence College and the Samsovitch College of Intelligence Gathering.
 War Academy of Mars
Another member of the War Triad, the War Academy of Mars also functioned as the strategic headquarters of the SLDF. Constructed in 2601, it was located in a huge canyon about 100km southeast of Olympus Mons. In addition to vast complex of buildings, spaceports and battlefields, the cliffs of the canyon were hollowed out for additional room, including hangers and machine shops.
In the first months of the Amaris Civil War, the officers and cadets of the War Academy fought off the 23rd Republican Dragoons for six weeks until, in frustration, the Republican commander ordered a nuclear bombardment to wipe it out. The only surviving structures, a few sheltered buildings and some of the cliff-based hangers, were ransacked in the aftermath.
 Military Academy of Aphros
The Military Academy of Aphros was the third member of the War Triad, located in Aphros, the capital of Venus. Constructed in 2242, its primary responsibility was training fighter and DropShip pilots, as well as one of several institutions overseeing the Gunslinger Program during the First Hidden War. The academy was destroyed during the first months of the Amaris Civil War by nuclear bombardment.
 Combat College of New Earth
The Combat College of New Earth was the first military academy built on an alien world, New Earth. Constructed in 2331, the Combat College maintained a rivalry with Sandhurst Academy until it was destroyed in the Amaris Civil War.
 Fleet School of Keid
 Flight Academy of Graham
 University of Proserpina
A very tradition-bound institution, the University of Proserpina was notable for graduating ten members of House Cameron. Indeed the basis of the university's unusual and rigid customs were formed by the actions of its Cameron graduates, resulting in officers with a very strong sense of snobbish superiority.
 Martial Olympiad
The Martial Olympiad was a series of mock combats held every four years from 2640 to 2736. The event was designed to test fighting skills and recognize the best units within the SLDF. It took place on the surface and in orbit above Mars, and later Outreach, and involved more than 100 "events" pitting regiments, divisions and space craft against each other. Precautions were made to prevent the loss of life, although deaths did occur, and while it was expensive to maintain the Olympiad was popular among troops as a way to display their skills and the public as a media event.
The uniforms of the SLDF were not only meant to identify the branch of service, rank and unit the soldier belonged to, but also foster esprit de corps. There famous stories of soldiers going to great lengths to protect their portable clothes-care machines to ensure their uniforms would not stay dirty, while the most shameful thing a soldier could do would be to commit a crime while wearing their uniform. In response citizens of the Star League gave soldiers in uniform great respect, and took to copying elements of their uniforms into business suits, jackets and dresses in what fashion designers called the "Trooper Look." Pieces of SLDF uniforms would survive after the organization's demise in the uniforms of the five Great Houses.
|Lieutenant General/Rear Admiral|
|Major General/Vice Admiral|
|Commanding General/Commanding Admiral|
 Second Star League Defense Force
In late 3058, the leaders of the Inner Sphere decided to resurrect the Star League in order to defeat the Clans. Victor Steiner-Davion became the first Commanding General of the SLDF since General Aleksandr Kerensky, though the SLDF was composed of only a handful of units. In 3063, Victor resigned as Commanding General in order to avoid a conflict of interest while he led forces loyal to him against his sister, Katherine. Hohiro Kurita succeeded Victor and presided over the disbandment of the SLDF following a vote of no confidence in the Star League in December of 3067.
 Units of the Second Star League Defense Force
Though the ultimate goal of the Second Star League was to create a wholly independent SLDF, due to the small number of so called "core" units, the organization relied heavily upon preexisting units from each member-state. Such units were donated for fixed periods of service and operated per the SLDF Chain of Command. 
As a surviving remnant of first SLDF renowned for maintaining the traditions and history of the original, one of their first acts of the Second Star League was to offer the Eridani Light Horse mercenary unit a place in the new SLDF. The ELH accepted, and made its headquarters in Fort Dieron. In addition, the commanding officer of the ELH was promoted from Brevet General to Lieutenant General.
- Command and Transport Division
- 71st Light Horse
- 151st Light Horse
- 21st Striker Regiment
- 19th Cavalry Regiment
Born of a centuries old secret society within the Northwind Highlanders devoted to maintaining the traditions of the original Black Watch Regiment destroyed in the Amaris Coup, the new Royal Black Watch again serves as the personal bodyguard of the First Lord.
The first entirely new unit commissioned by the Second SLDF, the 1st Royal BattleMech Regiment was formed by Andrew Redburn from the survivors of many of the commands that were destroyed as a part of Task Force Serpent's assault on Huntress. Most of these troops came from the 1st Kathil Uhlans.
Pledging their allegiance to the reborn Star League, the Abjured Clan Nova Cat was still a force to be reckoned with, contributing both elite troops and the bulk of their WarShip fleet to the defense of the League. While theoretically the entire Nova Cat touman fell under the control of the SLDF, per their agreement with the Draconis Combine a full third had to be retained within the Combine's borders for the defense of the Cat's Irece Prefecture. 
- ↑ The Star League, p. 92,
- ↑ The Star League, p. 96
- ↑ The Star League, p. 105 "Star League Defense Force"
- ↑ The Star League, p. 139
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 The Star League, p. 133
- ↑ Historical: Reunification War, p. 27
- ↑ 7.0 7.1 The Star League, p. 41
- ↑ The Star League, p. 139
- ↑ 9.00 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 9.09 9.10 9.11 9.12 9.13 9.14 9.15 9.16 The Star League, p. 129-130
- ↑ The Star League, p. 71
- ↑ The Star League, p. 131
- ↑ 12.0 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 The Star League, p. 132
- ↑ 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 The Star League, p. 108-109
- ↑ The Star League, p. 174
- ↑ The Star League, p. 178
- ↑ The Star League, p. 134-135
- ↑ The Star League, p. 110
- ↑ 18.0 18.1 Field Manual: ComStar, p. 75-76, "The Star League Defense Force"
- ↑ Field Manual: ComStar, p. 84-89, "Eridani Light Horse"
- ↑ Field Manual: ComStar, p. 97-98, "Royal Black Watch Regiment"
- ↑ Field Manual: ComStar, p. 101, "1st Royal BattleMech Regiment (Morgan's Lion)"