Vanguards

The Vanguards are a 28th founding loyalist chapter and successor to the Mentor chapter. They share some similarities with their parent chapter: they are are sometimes referred to as the “Vanguard Legion” in Imperial records and they specialize in advanced R&D, though their focus is primarily dedicated to vehicles. They have a fascination with aircraft and, like the Ravenwing companies of Dark Angel successors, they pilot their own aircraft, which is unusual among the Adeptus Astartes (as tech priests normally pilot them).
== Founding ==
Founded during the 28th founded, prior to the Ultima Founding, the Vanguard Legion was formed from excess Mentor Legion geneseed. They are not close with their parent chapter and and have a sort of rivalry with them. Like their progenitor chapter, they specialize in reinforcements, support, and field testing new technology- particularly vehicles.
=== Primaris Marines & The Ultima Founding ===
The Vanguards were reinforced with four full companies of primaris marines, doubling their size. Rumor has it that the Vanguards were a secret testing bed for at least some of Belisarius Cawl’s experiments. If true it would account for the sudden appearance of four companies almost overnight. While the the initial four companies worth of marines of the Vanguard Legion still operate in much the same way they did prior to the Ultima Founding the four primaris chapters are treated in a much more codex-compliant fashion.
== Organization ==
The Vanguard Legion does not comply with the Codex Astartes as it would inhibit their mission. There are three components to the chapter: the field teams, the squadrons, and the battle companies.
The first three chapters worth of marines  are organize into small “field teams” to provide aid, education, and to test new equipment. Like the Mentors Vanguards are loaned out to other organizations, often armored companies, as auxiliaries. They bring with them a host of specialized technology, training, and vehicles. While they do the observational and research duties that their parent chapter does, they have a daredevil’s streak and like to gain in the field testing of dangerous new equipment.
The field teams are reorganized as the needs arise, though they are typically the size of a tactical squad (5-10). One’s general standing is denoted by their rank. Each team is lead by a sergeant, though larger deployments will be overseen by lieutenants, particularly if there are a number of components in a given deployment that need to be overseen with greater detail. In such instances, such as three tanks being tested at once, sergeants will oversee field teams of various sizes. The only formal “squad” that exists is a single command squad within each company. This is done to allow administrative functions of the chapter and the company. All field teams are nominally part of the 1st company.
The second compliment the chapter maintains is represented by the 2nd company. This company is home to the chapter’s aerial squadrons. Members from the field teams and battle companies are sometimes are reassigned here and vice versa. The chapter has a proud tradition of combat aviation and the 2nd company exemplifies this. Their squadrons of vanguard striker fighters are easily on par with any from the Ravenwing if not their superiors. They have only a few tactical squads (normally seconded from the battle companies) that are utilized as drop troops. Like the field teams the 2nd company, or just elements,  is loaned out to other chapters as reinforcement.
The third element of the chapter is its four battle companies (the 3rd-6th companies). These are entirely of primaris marines and are organized like battle companies of a codex-compliant chapter. Like other elements of the chapter they are used mostly as reinforcements for other chapters. They diverge only in that they utilize aircraft, droppods, and other forms of aerial insertion as their preferred method of engagement with their foes.
There exists a company designed as a “company X” that serves as the scout company. In practice it is its own company but they are always attached to the 1st company. They are overseen by a Lt. who is referred to as the “Exalted Teacher” as is a senior member of the chapter master’s retinue and command structure.
The captain of the 1st company is treated as the senior captain, though they primarily are concerned with research and administrative matters and as such the captain of the 3rd company (being the veteran 1st battle company) is the de facto senior captain in military and deployment matters. He is referred to as the Battle Master and his authority on such matters is second only to the chapter master’s.
The chapter has some odd and exotic nomenclature for certain positions, denoting their specialist natures. The chapter master is referred to as their “Supreme Commander” and is supposed to oversee the combination of the three elements of the chapter (R&D, aviation, and the battle companies).  The captain of the 1st Company is referred to by the title of “chief technomancer” in deference to their seniority and the requirement that they must also serve as the chapter’s chief techmarine. There exists the title “ace” for marines of exceptional distinction in the 2nd Company and their Captain is referred to as the “Air Marshal”. The rank of “ace” doesn’t denote seniority (though they tend to be assigned to lead squadrons) but a certain level of skill. The Captain of the 3rd company, the 1st battle company, is referred to as the “Battle Master” and has authority over the battle companies of the chapter. The Lt. who oversees the scout company (the infamous “Company X”) is referred to as the “Exalted Teacher” (“Lt. Otto Mendel, Exalted Teacher”).
=== 1st Company (Field Teams) ===
Leader: Chief Technomancer Von Neumann
While formally a single company the 1st company has about 300 marines that are used to field field teams. All the tanks, including the superheavy ones, are organized under the 1st company though are sometimes seconded to other chapters
=== 2nd Company (Fighter Squadrons) ===
Leader: Captain Air Marshal Hartmann
The 2nd company is the designated combat aviation company of the chapter. All the vanguard strike fighters can be found in this company. A small number of drop-troops are often seconded to this company when undertaking solo operations. The 2nd company is not arranged in accordance with the Codex Astartes. They have a command squad, and an “armory” of aircraft.
Their basic tactical unit is the squadron that has 2-4 aircraft and a group is comprised of 2-3 squadrons. A group generally serve as the equivalent of a “squad” on the ground and is overseen by a Sergeant. 3 groups make a division and the 2nd company has 2 divisions, one overseen by a Lt. and one by the Captain of the company. All together the 2nd company has about ~40 aircraft, though it is rare that all of them are at use at once.
=== 3rd Company (1st Battle Company) ===
Leader: Battle Master Dyson
While not the “1st” company, the 3rd company is the 1st battle company and thus is treated like the chapter’s veteran company. The captain of the 3rd company is referred to as the chapter’s “Battle Master” and their authority is second only to the chapter master’s.
=== 4th Company (2nd Battle Company) ===
Leader: Captain Kepler 
Established as one of the four battle companies of primaris marines, the 4th company is a codex compliant battle company. They have a reputation for using plasma weapons and hellblaster squads.
=== 5th Company (3rd Battle Company) ===
Leader: Captain Galilie 
One of the companies of primaris marines, the 5th company (aka the 3rd battle company). They have a double-strength tank compliment.
=== 6th Company (4th Battle Company) ===
Leader: Captain Faraday 
As the last battle company the 6th is often the first stop for many new battle brothers. They are a codex-compliant battle company composed of primaris marines. Their high number of recent scouts gives them a reputation for being undisciplined and naive.
=== Company X (Scout Company) ===
Leader: Lt. Mendel (Exalted Teacher)
Designated as “Company X”, possibly because the company size of the chapter has fluctuated, the scout company is always attached to the 1st company. Prior to the Ultima founding Company X didn’t exist and it is speculated that Company X was the designated company for the proto primaris marines of the chapter (if they did, indeed, serve as a testing ground for them). Company X fluctuates in size from a half company in strength to existing only on paper when no scouts are present.
== Vehicles ==
Vanguard Strike Fighters: The most famous vehicle in use by the chapter is their vanguard strike fighters. Working from the ancient STC of the Xiphon Interceptor, the chapter flies into battle at gravitational stress levels that would turn your average person to paste. These single-person fighter-jets are capable of both void and atmospheric flight. They lack transport capacity but compensate for it with an impressive array of firepower. They carry a twin-linked, extended range, lascannon in front of the cockpit and two additional ones on the wings. They have a large complement of plasma missiles and each craft is fitted with two hunter-killer missiles. Missiles can be swapped out for a wide array or bombs and rockets depending on the mission.
Crius: Before the Ultima founding the Vanguard’s best kept secret was the prototype of what would become the Astraeus super-heavy tank. Known as “Project Crius”, as Crius was a titan and the father of Astraeus in ancient Terran mythology. They experimented with a number of variants and refits before they arrived at the setup that would become standard for all future Astraeus tanks. Still designated as “Cirus”, they take immense pride in their tank. It is currently assigned to the 3rd company.
Repulsors: The Vanguards have several companies of Repulsor grav-tanks. One, assigned to the 1st company, is a repulsor variant similar in function to a Damocles Command Rhino and is designated as a Damocles Command Repulsors. It is typically assigned to the use of either the captain of the 1st company or the chapter master.
Grav-Raider Terminus Ultra: The Vanguards have four anti-grav landraider terminus ultra. Three are  assigned to the 4th company and one to the 5th.
Vindicator Laser Destroyer: The 5th company has one of these powerful tank-destroying variant of the Vindicator.
Predators: The 5th company has a large complement of predators.
== Notable Campaigns ==
Showdown at Cold Ridge: The Vanguards provided three fields teams to the Showdown at Cold Ridge between the forces of the Silent Gnosis chapter and the chaos forces under the command of the Dark Savior Klorphius the Hedgemon. After a nearly two month stalemate, a tank blitz broke the enemy’s line and allowed Chief Librarian Sermo Vita decapitated Klorphius and composed a ballard about it called “The Red March of Legion Treds”.
Extermination of Höllenschlund: A large pocket of Rangdan were discovered. They had ravaged an imperial world, conquered the entire system, and were breeding to start another large crusade that would have rivaled that of the xenos forces during the Rangdan Xenocides. A massive number of Imperial forces undertook the campaign of extermination on the Höllenschlund system. The Vanguard provided their forces, including the super heavy tank Crius, to the task.
Siege of Himmelstoss: A combined attack by the Mordian Iron Guard, Ilen 1st Armored Regiment, local planetary defense forces, and 5th Company (3rd Battle Company) of the Vanguards laid siege to the capital of Himmelstoss. Captain Galilie is noted for having provided technical insights and support with his Vindicators that were essential in saving (and later repairing) the super heavy tank known as “The Ire of the Emperor”. The planet was eventually lost and the 5th company suffered heavy casualties but a later campaign reclaimed it.
== Notable Vanguard Legion Marines ==
Supreme Commander Heinrich Sagan: The supreme commander of the chapter is Heinrich Sagan, a marine that has been with the chapter since its inception. If the rumors are to be believed he is actually a covert transplant from a different chapter, probably the Mentors, rather than of the gene seed of the vanguards. He is stern, stubborn, absolutely brilliant in every sense of the word, and is quite divisive in the chapter. He is aloof and spends much of his time in research and development, to the exclusion of the rest of the chapter’s duties. Many of the responsibilities that he undertook have fallen to the wayside and been taken up by the Battle Master and Chief Technomancer.
Chief Technomancer Carl Von Neumann: The “Chief Technomancer” is Captain Carl Von Neumann of the 1st chapter who has the venerated task of overseeing the deployment of field teams. He also fills the role of the chapter’s chief Techmarine and has considerable technical and theoretical knowledge that is rivaled by few in the Astartes. He was originally from Battle-Moon Don in the Kingdom of Keb (as as many Vanguard marines).
Ace Pierre Clostermann: The hottest stick in the chapter, Pierre is relatively young by marine standards but has hundreds of kills, some of very important targets, to his name. Pierre is widely regarded not only as the best pilot of all the astartes forces but also the finest pilot in the Imperium (if not the universe). Unfortunately, he is a lone wolf and a bit of a hot shot who bucks at any sort of authority. He’s been shot down dozens of times and cost the chapter valuable time and resources to recover him. With his skill he could probably be the captain of the 2nd company but his lack of discipline has kept him at the level of squadron leader. His squadron, known as “Jolly Roger Squadron” is the most celebrated squadron in the chapter and be identified by the skull and crossbones on the tails of their strike fighters. He’s been given the title of “ace” and trains new members of the chapter in the handling of aircraft. At one point Pierre was on track to become a techmarine, though those plans have indefinitely put on hold as he is too valuable for the chapter’s military efforts.