Weakest Factions In The Lore

The galaxy of Warhammer40k is filled with factions that are battling to survive, conquer, or fight simply because it is in their nature. In the grim darkness of the far future, there is only war. Every faction in Warhammer has the ability to defeat another. Species rise and fall like the tides of the warp. None of these factions are truly weak.

The weakest army may still rule an empire of thousands of worlds, but against the tide of countless enemies coming from every direction, not every faction can be considered equal in strength. Many factions within the galaxy have the potential to rise beyond their current standing and expand, while others are playing a different game altogether.

Updated February 10, 2024 by Andy Chapman: The setting of Warhammer 40k is in constant motion. With the release of the 10th Edition in June 2023, 40k has grown in popularity and continues to reach new audiences. Also, with this release, the lines of power have been redrawn in the setting. As Chaos emerges victorious over the Dark Angels, they have gained a mysterious new weapon. Meanwhile, the Tyranid Hivefleet Leviathan continues to devour its way across the stars, seemingly unstoppable. To expand readers’ knowledge of the setting, this article has been updated with more information and additional entries. These additions give a better picture of the weaknesses of each faction and where they stand in the power struggle of the galaxy.

12 Chaos

The Chaos Gods Fight Among Themselves

• Faction Leader: Chaos Gods, Abaddon The Despoiler (Chaos Marines)
• Main Enemies: Imperium Of Man, Aeldari

The forces of Chaos may represent the greatest danger to the wider galaxy out of all the other factions. Ultimately, they cannot be defeated, as they are creatures of the immaterium. Killing a demon sends it back into the warp, but eventually, it will return.

The main fighting force of this faction, the Chaos Space Marines, are less numerous than others and aren’t fully united. Infighting is common, and that always weakens a faction. The chaos gods they follow also have other priorities. They play “the great game,” always trying to one-up each other to gain more power. The empires of mortals are often irrelevant to their plans.

11 Orks

Disorganized, With Lots Of In-Fighting

• Faction Leader: Ghazghkull Mag Uruk Thraka
• Main Enemies: Anyone they can find

Ancient and war-hungry, the Ork race is one of the most dangerous factions in the 40k setting. Created by the Old Ones, the Orks have devolved over millions of years into dim-witted brutes that only exist to fight.

Known as the Green Tide, the Orks, if unified, would sweep over the galaxy. They could destroy everything in their wake, with no one being able to stop them. Luckily, they’re not very unified. Killing a warboss will usually put an end to any significant threat. The Orks live to fight and will happily scrap among themselves if necessary.

10 Adeptus Astartes

Small Independent Chapters

• Faction Leader: Various Chapter Masters, Imperial Regent Roboute Guilliman
• Main Enemies: Everyone in the galaxy that isn’t human

The Adeptus Astartes, better known as Space Marines, are the genetically enhanced elite super soldiers of the Imperium. After the Horus Heresy, the Astartes legions were split into smaller chapters, each containing around 1000 marines. Each of these chapters is an independent body, with its own unique customs and preferred methods of war.

Within the current setting and the opening of the Great Rift, many of these chapters have been lost. Several have gone silent or been decimated by chaos. As an overall faction, Space Marines are among the greatest warriors in the galaxy, but as smaller self-contained chapters, they can be vulnerable to larger forces if caught unawares.

9 Astra Militarum

Average People Who Fight Strong Opponents

• Faction Leader: Lord Commander Solar Arcadian Leontus
• Main Enemies: Everyone in the galaxy that isn’t human

The Astra Militarum consists of billions of humans from a million different worlds, who defend the Imperium of Man. These are average men and women often armed with the most basic weapons. If the entire might of the Militarum was sent to fight a single battle, they would always win due to their massive numbers.

Yet with humanity fighting on almost every front, this is still not enough to hold back the tide. More often than not, the Militarum is outgunned and spread too thin, pitted against foes that hell itself spat out.

8 Necrons

Most Are Still Asleep, So No New Necrons Will Be Born

• Faction Leader: Szarekh, The Silent King
• Main Enemies: Humanity, Aeldari

The Necrons are one of the older races in the galaxy and are cursed to exist as living metal skeletons. Millions of years ago, The Necrontyr were tricked by a race called the C’Tan. Their souls were devoured, and their bodies and consciousness transferred into the metal form of the Necron.

This faction represents one of the greatest potential threats in the 40k setting, but currently, the majority of the race is still in stasis, waiting to rise and reclaim dominion. Until that time, the Necrons are a lesser faction.

7 Aeldari

Smaller Numbers Spread Over The Galaxy

• Faction Leader: Craftworld Farseers, Yvraine (Ynnari)
• Main Enemies: Chaos (Slaanesh)

The Aeldari represent the remnants of the Eldar race as it once was, before the fall and the coming of Slaanesh. Surviving on vast continent-sized ships known as craftworlds, the Aeldari are now a cursed people. With every death, their souls are sucked into the warp and devoured by Slaanesh.

The Aeldari are some of the strongest psykers in the setting, and still retain much of the technology that made the ancient Eldar so powerful. They are also a shadow of their former civilization, clinging on to existence as their species dies out.

6 Drukhari

Smaller Numbers Mainly Living In The Webway

• Faction Leader: Asdrubael Vest
• Main Enemies: Chaos (Slaanesh)

Among the many sub-factions within the Eldar race, the Drukhari are some of the most depraved and feared in the galaxy. During the fall, when the chaos god Slaanesh was born into existence and the Eldar race came close to extinction, the Drukhari were safe within the webway.

To save their souls from being devoured by the chaos god, the Drukhari torture countless innocent beings to appease Slaanesh. They are a small faction, that usually raid planets than conquer them, and rarely get into full-blown wars.

5 The T’au Empire

Smaller Numbers Compared To The Big Factions

• Faction Leader: Ethereal Supreme Aun’va
• Main Enemies: Orks

The T’au Empire is an expanding race of xenos. Unlike many other factions, they embrace other species into the fold of their empire and believe in the notion of the greater good.

Within the setting, they are one of the younger races to spread into the galaxy, and have limited knowledge of the wider dangers. They’re a smaller empire in comparison to some of the other big players. Due to their limited warp capabilities, they have not been able to expand as fast as others and have often been left alone.

4 The Leagues Of Votann

Smaller Numbers, And Their Leaders Are Slowly Dying

• Faction Leader: Votann (AI Machines)
• Main Enemies: Orks, Chaos

The Leagues of Votann are an ancient and secretive race of abhumans who originally settled deep within the relative safety of the galactic core. They possess extremely advanced technology. As a people, they refer to themselves as The Kin and are led by hyper-intelligent AI constructs known as Votann.

This faction has the technology to go up against any foe. But with fewer numbers to call upon, and with more Votann degrading beyond repair every passing year, it is only a matter of time before the Kin are in serious danger.

3 Adeptus Mechanicus

Dependent On The Imperium For Long Term Survival

• Faction Leader: Fabricator General of Mars
• Main Enemies: Chaos (Dark Mechanicum)

The Adeptus Mechanicus of Mars is a rarity within the Imperium, as they retain much of the independence they had before the unification of Terra by the Emperor of Mankind. They are a secretive cult that worships the machine god called The Omnissiah. Their main task is to build and maintain the vast majority of the warships, weapons, and technology for humanity.

The relationship between Terra and Mars is a symbiotic one, with each being unable to exist without the other. Terra relies on Mars for its technology, while Mars relies on Terra for its strength. The Adeptus Mechanicus is a power unto itself, able to wield weapons of indescribable destruction. However, they do not have the numbers Humanity can call upon, and would be overwhelmed by almost every other faction in the setting.

2 The Adepta Sororitas

Smaller Numbers Of Average Humans Going Against Stronger Opponents

• Faction Leader: Abbess Sanctorum Morvenn Vahl
• Main Enemies: Anyone who doesn’t worship the Emperor as a God

The Adepta Sororitas, more commonly known as The Sisters Of Battle, are a warrior order of religious nuns that fall within the wider Imperium of Man. Known for their ability to perform faith-based miracles during battle, The Adepta Sororitas is as feared as it is celebrated.

Often sent to bring down uprisings within the imperium, they are some of the greatest warriors of humanity. But unlike the Astartes, they are not augmented super soldiers. Going up against some of the larger threats of the galaxy, on their own, they do not have the strength.

1 Genestealer Cults

Small Numbers That Can Be Stopped Before They’ve Begun

• Faction Leader: Genestealer Patriarch
• Main Enemies: Imperium Of Man

Genestealer Cults represent a growing danger within the Imperium of Man. Unlike other factions that attack overtly, a planetary system can be overrun before the Imperium even knows a problem exists. Like a sickness, cults grow slowly, infecting the population until they are large enough to overrun the world.

Genestealer Cults are led by a single breed of xenos known as a Patriarch. This large and dangerous pure strain of Genestealer is the source that starts an outbreak, which means killing the Patriarch stops the uprising.