Welcome to Warhammer 40k - Lexicanum! Log in and join the community.

Imperial Navy

From Warhammer 40k - Lexicanum
(Redirected from Divisio Aeronautica)
Jump to: navigation, search
Fleets of the Galaxy : Imperial NavySpace Marine FleetAdeptus Mechanicus FleetChaos FleetEldar FleetDark Eldar FleetOrk FleetTyranid FleetNecron FleetTau FleetTau Merchant FleetLeagues of Votann Fleet
Navis Imperialis (Imperial Navy)
Parent Agency Imperial Fleet
Headquarters Naval Headquarters, Terra
Leader Lord High Admiral of the Imperial Navy
Established Post-Horus Heresy, M31 (preceded by the Imperialis Armada)

The Imperial Navy, or Navis Imperialis[15] in High Gothic, is one of the armed forces employed by the Imperium. While the Astra Militarum (or Imperial Guard) is responsible for the Imperium's ground forces, the Imperial Navy is responsible for the fleets of warships that soar between the stars and planets in the Imperium as well as engaging threats both inside and outside the Imperium's borders. The Imperial Navy is the military arm of the Imperial Fleet[1] and was, until their separation after the Horus Heresy, a branch of the Imperial Army.


During the early Imperium in the Great Crusade-era, the Imperial Navy was originally a subbranch of the Imperial Army known as the Imperialis Armada. During this time, the Imperialis Armada was primarily used for the defense of Imperial space while planetary invasion was left to the fleets of the Legiones Astartes.[19] However after the devastating Horus Heresy, which saw widespread rebellion from within the Army, Lord Commander of the Imperium Roboute Guilliman felt it prudent to separate the Army and Navy in order to lessen the threat of future insurrections.[17][18]



Fleet Structure

The Imperial Navy is organized into five fleets, each assigned to one of the Segmentae Majoris. Each fleet is named for the Segmentum in which they are based, such as the Battlefleet Solar.

These fleets are then subdivided into smaller fleets patrolling individual sectors and subsectors, and are also generally named after the area they safeguard. For example, Battlefleet Gothic protects the Gothic Sector.

The Imperial Navy administrative center is the Naval Headquarters on Terra.[9]

Fleet Headquarters

Fleet Personnel

A Navy officer

The Imperial Navy is headed by the Lord High Admiral of the Imperial Navy, who is often one of the High Lords of Terra. He oversees five Segmentum Lord High Admirals.

Below the Lord Admirals are various Sector and Battlefleet commanders, then individual ship Captains and junior officers, and finally a myriad array of Non-Commissioned Officers. The Imperial Navy has a corps of Commissars that oversee the morale and discipline of Naval personnel, known as the Fleet Commissariat.[6]

The Imperial Navy also operates Naval Security Battalions, also known as Naval Armsmen[6]. These consist of units of armed soldiers intended to put down mutinies, board enemy ships, and protect Imperial Navy installations. Typically, Naval Security troopers are equipped with black body armour and shotguns.[4]

Imperial Navy vessels require personnel from other Imperial elements to function. These include Navigators from the Navis Nobilite for navigation[13], Astropaths for interstellar communication[14], and Tech-Priests from the Adeptus Mechanicus for higher maintenance[14]. One of the foremost duties of the Navy is to transport the Imperial Guard to warzones, and as such, every Navy vessel, no matter how small, will sport some means of training deck to accommodate them.[11b]

The lowest level of personnel in the Navy hierarchy are bondsmen, who are little more than slaves. Alongside Servitors, these poor souls undertake the most thankless and dangerous tasks on a vessel. Bondsmen are acquired by various means, such as rounding up criminals or unsavory elements of Imperial society or simply being born into their status aboard a vessel. Bondsmen's duties include cleaning, hauling ammunition into weapons chambers, shoveling fuel, and manual labor. Working long hours and only fed meager rations, Bondsmen are met with brutal discipline should they protest their status.[11a]

Imperial Navy workers load a Torpedo into its firing tube[12]


The Imperial Navy deploys a vast diversity of vessel types, from one-man attack fighters to kilometers-long Battleships.


Emperor Class Battleship

Battleships are colossal vessels with significant weaponry and shields. They usually serve as the flagship for the Admiral of the Fleet, though this is not always the case. Although very powerful, battleships are slow to manoeuvre and cannot react quickly to enemies that rapidly change course. Imperial battleships can have crews of between 25,000 to 3,000,000 or more depending on sources, including large numbers of Imperial Navy armsmen to defend against enemy boarding assaults. Battleships can be up to 8 kilometres from prow to stern and displace billions of tons. Because they represent such a vast expenditure of resources and require a fairly advanced technical base, these are typically constructed only in the largest shipyards above the major Adeptus Mechanicus Forge Worlds. These vessels are precious assets and are carefully husbanded, usually employed in only larger fleet formations.[2]

There are various classes of Imperial Battleship, but the Emperor and Retribution are by far the most common in the Imperial Navy.


Smaller than Battleships, Cruisers are the ships of the line in Imperial Fleets. There are several different sub-categories of Cruiser.

Grand Cruisers

Vengeance Class Grand Cruiser

Grand Cruisers are significantly smaller than battleships yet distinctly larger than regular cruisers. These vessels are usually very old in design, do not incorporate many features typical in current Imperial Navy vessels, like armoured prow, and are not entirely compatible with current Navy tactical doctrine. Due to this, many are retired from active duty but are still used by reserve fleets. There are also some modernised versions of grand cruisers in service, but since they are much larger and more heavily-armed than their predecessors, they are often classed as battleships. These kinds of vessels are usually purpose-built or modified from battlecruiser hulls and are not commonly encountered in the Imperial Navy.[2]

Battle Cruisers

Armageddon Battle Cruiser

Battlecruisers are based on a hull design that is similar to the regular Cruisers, though Battle Cruisers are generally somewhat larger and more heavily armed, incorporating more advanced power distribution systems capable of supporting battleship-grade weaponry in a cruiser hull.[2]


Dominator Class Cruiser

Cruisers make up the majority of a fleet. Though not as powerful as a Battleship, cruisers are much faster and can still deliver a deadly blow. There are multiple classes of cruisers, most based on the same general hull design but incorporating different combinations of broadside batteries, lance turrets and starfighter hangars. Cruisers can carry a crew complement of 1,000-100,000[3], depending on sources. While cruisers are still particularly complex, it is not uncommon for them to be constructed on smaller Forge Worlds or any Civilised World with a shipyard suitable for constructing vessels of their size.

Light Cruiser

Endeavour Light Cruiser

A subset of the cruiser category are the Light Cruisers. These ships fall in size between cruisers and escorts, mixing the firepower and durability of the former with the speed and manoeuvrability of the latter. Light cruisers are a fairly common ship class, for they are relatively simple to construct for being a capital ship, and they are uniquely suited for reconnaissance patrols and for making a presence where their speed and manoeuvrability are an advantage and where having a larger number of smaller hulls allows the Navy to monitor a wider area of space.[2]


Escort Vessels

Escort ships are the smallest type of ship in the Imperial Navy fleets, found in two distinct sub-classes.

The larger of the two are Frigates, better armed and more heavily armoured. Destroyers are generally smaller, but they are by far the fastest and most manoeuvrable interstellar warships employed by the Imperial Navy. They are usually organised in squadrons of 2 to 6 vessels and will always operate as a group. The main task of the escort ships is to serve as a screen for capital ships against enemy torpedoes and attack crafts so that they can get into position more quickly and safely. They are also employed behind the gun line to finish off enemy cruisers that have been damaged so that the larger vessels can concentrate on the most important threats in an enemy formation. Most escort classes specialise in a certain role, such as the Cobra class torpedo boat destroyers or the Firestorm class frigate with its armour-piercing prow-mounted Lance. Escort ships are normally not more than 1.5 kilometres in length, with destroyers generally being only 750 metres to 2 kilometres from prow to stern.[2]

Older and obsolete classes

There are many older classes of Imperial ship that are no longer in production -

  • Ironclad Battleships - also known as Adamanticlads much like their contemporary counterparts, are vast 8-kilometre vessels which lack the void shielding of their counterparts in favour of metres of adamantium plate armour. These ships, built before the advent of void-screen technology, have since been phased out of production, for the main part, to be replaced by more modern designs.[7]
  • Obsolete Classes - There are many classes of vessel which were once utilised by the Imperial Navy. Many of these older vessels are still in service with the Traitor Fleets.

Note on variations in Classes

While naval warships can be defined along a fairly limited number of classes based on weapon configurations approved by the Adeptus Mechanicus, the form these vessels takes varies widely throughout the Imperium. For example, a Lunar class constructed above Cypra Mundi in Segmentum Obscurus may bear little resemblance to a Lunar class constructed above Kar Duniash in Ultima Segmentum and even less so to a Lunar class, constructed among the vast shipyards of Mars. Nonetheless, they will all have roughly the same operating characteristics and weapon configuration, and thus can be easily serviced by any orbital facility throughout Imperial space.[Needs Citation]

Attack Craft

An Imperial Navy landng party

Many Imperial vessels carry onboard various smaller craft for both offense and defense.


The branch of the Imperial Navy known as the Aeronautica Imperialis is responsible for the majority of Imperial Aircraft. These aircraft are used both for space-combat and providing air support to Imperial ground forces.

Aquatic Vessels

The Imperial Navy also fields aquatic vessels such as Naval Battleships.[10]

Imperial Navy Equipment

Notable Members of the Imperial Navy


See also



Modern Imperial Organizations
Adeptus Terra Adeptus Administratum (Adeptus AstartesDepartmento MunitorumAstra MilitarumOrdo TempestusImperial FleetImperial NavyMerchant FleetPraeses MercaturaNavis NobiliteOfficio AssassinorumEstate ImperiumTemplars PsykologisOfficio SabatorumOfficio MedicaeOfficio AgricultaeOfficio LogisticarumDepartmento ExactaAstra CartographicaLogis StrategosDepartmento ColoniaDepartmento ProcessiumDepartmento of Final ConsiderationDepartmento ContagioDepartmento GradioQuestio LogisticusRogue TradersImperial Commanders) • Adeptus Astra Telepathica (Sisters of SilenceLeague of Black ShipsScholastica Psykana) • Adeptus AstronomicaAdeptus ArbitesAdeptus CustodesQuestor Imperialis (House Guard) • Adeptus FidiciusSynopticon
Adeptus Mechanicus Cult MechanicusCollegia TitanicaLegiones SkitariiQuestor Mechanicus (House Guard) • Centurio OrdinatusOrdo ReductorLegio CyberneticaAuxilia MyrmidonPrefecture MagisteriumBasilikon AstraDivisio LinguisticaExploratorSect Missionarius MechanicusCollegiate ExtremisAstynomia
Adeptus Ministorum Holy SynodAdepta Sororitas (Sisters of Battle) • Schola ProgeniumMissionarius GalaxiaCreed TemporalFrateris Militia
Inquisition Ordo MalleusOrdo HereticusOrdo XenosOrdo Minoris