The Borg don't really seem like the type to hold back and in the tiny bit we saw of the delta quadrant in Voyager there were a lot of races technologically inferior compared to the Borg. So the fact that they aren't expanding as fast as they would seem to be able to is a conundrum to me.

Memory Alpha lists the earliest recorded existence of the Borg as being 1484 (although their link doesn't include any details) and at the very least the Borg existed in the year 2063 (First Contact). While it could be said that their methods of assimilation may not have been very efficient in the earlier years, thus providing a potential impedance to their rate of expansion, some time prior to their introduction to the Federation, in the TNG episode Q Who, they had developed a level of technological superiority that any resistance to a major offensive by any known race would have been completely futile.

All of this would seem to indicate that the Borg are for some unknown reason restricting the rate of their expansion. Is there any known reason for this?

  • 13
    I blame the writers and their insistent demands of this thing called "plot." It would be a boring series if all they had to do was find an intelligent species, travel back 10,000 years and assimilate the species\culture before it has a chance to technologically develop... or for that matter "waste" all those precious resources building starships and forming "Federations."
    – erdiede
    Commented Sep 30, 2011 at 23:23
  • 3
    Because that would go against Star Trek's theme of promoting diversity. The Borg do not support equal rights. They're all about conformity.
    – BBlake
    Commented Oct 1, 2011 at 4:32
  • 2
    @Izkata Yes I agree to the idea of many cubes... I always thought it would make more sense to throw several dozen cubes at a difficult target through transwarp conduit, establish a beachhead, then begin assimilating from a nodal position working outwards. Of course, if the writers REALLY wanted to make sense you would have prepared assimilation "pods" to beam people to. Scan a ship, beam off its crew, then have Borg board and analyze the ship. Just my two cents and 300ish characters
    – erdiede
    Commented Oct 2, 2011 at 2:55
  • 1
    Hm, I was just curious and looked it up: The Borg cube that delivered the time-travel Sphere in First Contact arrived in Federation space on Stardate 50893.5, and Voyager encountered the Borg after their conflict with Species 8472 already began: Stardate 50984.3 - How far apart are those dates, and could the Borg's conflict with Species 8472 have already started, hence sending a single Cube during First Contact? (EDIT: Also, it was established in Scorpion that the Borg are incapable of research)
    – Izkata
    Commented Oct 2, 2011 at 3:05
  • 50
    Wait you guys aren't Borg?
    – AncientSwordRage
    Commented Jun 21, 2012 at 22:58

9 Answers 9


The Borg are choosy eaters.

They are likely several reasons the entire Milky Way Galaxy has not been converted into the Borg Collective. They include:

  1. The Borg's Transwarp Network while vast and covering thousands of worlds, it is still only a tiny margin of the potential worlds of the Milky Way. Borg space has been considered to be as extensive or a tiny bit larger than all of Federation Space.

  2. The Borg are likely searching for races with technological and biological distinctiveness which give the Borg a decided advantage and make that race worthy of absorption into the collective.

  3. All of those worlds in its space are not likely converted because once a world is converted, all of the developments (the technological one's for certain) are dead due to the loss of individuality. There are no longer any new advances being developed by that species, unless the Borg allow it to retain individuality. (But they would not be Borg, so that isn't likely.)

  4. Curiously enough, a race which offers promising technological developments will likely be allowed to continue to develop and merely watched by the Borg if those developments could either be stolen, bought, or reverse-engineered as long as that race was creating new ideas or technologies.

The Borg were known for plundering interesting tech from worlds on the edge of their space, or from races they could not or chose not to absorb for whatever their reasons. That could be their technological superiority, numerical superiority or because they created technology that made them too useful to bring directly into the fold of the Collective and "Borg-ified".

When a race was deemed near the end of their creative lifespan and had resources which would enhance the Borg's technological or sociological footprint in a sector of the Galaxy, it makes sense to absorb that world and take over that Empire by taking over the worlds that control it. This potentially could ease the transition or destabilize the potential target enough to make it easier to absorb.

If the race were significantly dangerous or powerful, the Borg might avoid them until they could find a means to defeat them as they forced to do with Species 8472 in the Delta Quadrant of the galaxy. Mortal enemies, technologically equal, each struggled unsuccessfully for dominance over the other.


Humanity having proven they were capable of developing technology that was at least marginally interesting to the Borg, and in the Borg's opinion potentially able to extinguish itself, was a prime candidate for absorption since, if Humanity in conflict with other races of the Alpha Quadrant were destroyed, the Borg would lose both significant manpower and technological advantages unique to the Alpha Quadrant.

The Borg even went so far as to develop Locutus (the Borg-ified Jean-Luc Picard during their first invasion of the Alpha Quadrant) and other Borg Uniques (the Borg Queens, for example) to treat with Humanity, perhaps to ease the transition of becoming subjected to the Borg's absorptive nanite technology.

To a race that has not developed great technology or has insufficient physical capability, the Borg would be more likely to send a message like this one: "Your species biological and technological distinctiveness isn't enough for us to absorb you. Yet."

  • 8
    That's a good point you make Thaddeus. It reminds me... Wasn't there a line somewhere in Voyager where 7 said something about how the Kazon were too primitive to be worth assimilating?
    – eidylon
    Commented Oct 1, 2011 at 1:05
  • 3
    That's correct, the the Borg considered the Kazon too violent and did not have enough technology that was unique enough to make them worth the effort to absorb. Commented Oct 1, 2011 at 1:34
  • 10
    I like your answer. Also, using one of your own logical options the Borg may have simply been acting in a manner to force the Federation to adapt, thus creating additional interesting technology at an otherwise increased pace (when compared to their rate of advancement when dealing soley with alpha quandrant races). When considering the advancements in weapons, ship designs and support technologies from the start of TNG to the end of Voyager this almost seems a possibility.
    – Xantec
    Commented Oct 2, 2011 at 4:40
  • 17
    The most successful virus or other pathogen doesn't kill their host(s) too quickly, otherwise they'd have nowhere to go, dead-end and die. They balance mortality/morbidity with transmission. You could perhaps draw similar parallels with the Borg.
    – Nick T
    Commented Nov 17, 2011 at 2:23
  • 7
    I like this idea of the Borg farming civilizations for useful technology until it's time to "harvest". Although it's a dangerous game - the Borg walk the fine line of assimilating too early and not gaining useful technology for their efforts, or waiting too long and the civilization becomes a threat. Actually sounds like the makings of a fun strategy game!
    – RobertF
    Commented Oct 21, 2014 at 18:41

Seven of Nine (in Voyager) has made references to some sort of calamity about 800 years prior to the series, and the Borg lost nearly all their records of the time. Most likely, they were nearly destroyed. After such an event, and especially after their encounters with Species 8472, they most likely don't want to spread too thin and risk destruction again.

Also, just because the assimilation process is fairly quick, doesn't mean there's an infinite supply of bodies. They're limited by available resources, just like us.

  • 3
    and even if assimmilation of a single lifeform is quick, it still consumes resources. Production of nanites must take time, so each borg drone can no doubt only assimmilate a limited number of target individuals in any given interval despite the short duration of the procedure. Thus while converting a single ship might only take an hour, an entire planet would require a massive logistical effort.
    – jwenting
    Commented Oct 3, 2011 at 9:55
  • 1
    And the development of infrastructure, such as ships and structures, is undoubtedly even slower. Better to simply leave a planet unassimilated, than to assimilate a million new drones in a year and then spend the next 20 years Borg-ifying the planet itself on principle.
    – Nerrolken
    Commented Sep 27, 2014 at 0:33

I always saw a singular flaw with the Borg. Despite the different Borg Queen's rationalizations given to Picard, Data and Janeway, the entire concept of the species was 'illogical'. That comes in by what Thaddeus brought up as the Borg primary objective, 'absorbing species which display useful technological skills and advancement.

When absorbing a species and their potential is rendered inert thus causing the Borg to constantly search for new species advanced or advancing to a level deemed useful. Though life seems prevalent in the STU, advanced interstellar cultures are rare.

Though it is unclear how old the Borg as a species are since their origins have never been discussed, pillaging and absorbing cultures the way they do is impractical. Everything written about the Borg suggests they are highly logical on an order superior to Vulcans. Any species with that level of logic based on a cybernetic culture would recognize their method of acquiring 'new blood' was inefficient. Though the Borg are highly adaptable, they cannot innovate which is why the Federation has been able to thwart them time after time.

I also found that Species 8472 being unable to overcome the Borg was also illogical. It was clear from their introduction they had the tactical and technical advantage over the Borg. They also proved to be innovative by creating that training center whereby they copied San Francisco, Starfleet Academy, Starfleet HQ and took human form to learn more about the 'human experience' in order to infiltrate Earth.

The Borg would never have wasted time or resources on something so elaborate. Even with their Transwarp Conduits, the Galaxy is unbelievably vast and they could go hundreds of years without finding suitable species to absorb. At least ants know to cultivate 'herds' of livestock (aphids) or crops (fungi) to sustain their colonies. The Borg seem much too simple and opportunistic to be so advanced a species capable of long-term viability.

  • 1
    Does this answer consider that the Borg grow new drones?
    – user15742
    Commented Jul 25, 2013 at 22:37
  • 8
    Who said the Borg can't innovate? A Borg individual can't innovate, because the entire collective would know what its thinking. But that doesn't mean the collective can't come up with far more complex ideas than any individual, Borg or otherwise, could.
    – nomen
    Commented Jun 8, 2014 at 3:26
  • 3
    @nomen is right, and I'll add that there is a fine (often nonexistent) line between innovation and extrapolation. If I steal the idea of the wheel and then I invent a wagon, was that an innovation of mine, or simply an extrapolated refinement of stolen tech? When the Borg assimilate a new race they don't just take their designs as-is, they take the ideas and adapt them to the needs of the Collective, no doubt developing them in new and unexpected ways in the process. Thus, they live by stealing tech, but they aren't impractically reliant on the innovations of other races.
    – Nerrolken
    Commented Oct 20, 2014 at 21:17
  • The Borg's goal is to achieve perfection, not territorial conquest or population expansion.
  • The Borg actually control a pretty significant chunk of space, and considering how densely populated the Milky Way is in Star Trek, they've assimilated quite a large number of species.
  • The Borg aren't as perfect as they appear to be. They don't make the most effective long-term use of their assimilated knowledge. They have civil wars. They lose battles. They lose contact with parts of the collective. They're not politically savvy at all and are moderately competent strategists at best (the exact opposite of the Dominion, which can conquer civilizations without them even knowing it). Their technology can fail. The list goes on and on...

Even if the Borg were actually interested in being purely expansionistic and also learned to employ the advantages of individuality (which the Queen seemed to be toying with) and were able to grow beyond their brute-force approach to conquest, there's still no quantitative data available to judge whether their rate of expansion is realistic or not.

  • Good points. To be fair though the Borg, to our knowledge, never had civil strife before interacting with the Federation.
    – Xantec
    Commented Mar 22, 2014 at 13:15
  • @Xantec: True. But it does suggest that the collective isn't totally invulnerable to civil conflict. It happens on a small scale when Hugh was re-assimilated, and then on a much larger scale 7 years later when Unimatrix Zero emerges. Commented Mar 23, 2014 at 1:38
  • 1
    The first bullet point largely addresses a potential Answer, so good job making that. In Voyager, the Borg were noted as having high interest in some super-particle, which destroyed many Borg ships, but the Borg continued to have interest in their pursuit of "perfection". We just don't know how many other goals the Borg might have. Isn't it nice to know that your home planet gets to temporarily survive longer only because it isn't suitably interesting?
    – TOOGAM
    Commented Dec 8, 2015 at 19:04

Because that is not their goal. The Borg, at least in the main canon, have never shown any interest is turning everyone into Borg, and in fact have demonstrated the opposite.

We know of many species which the Borg ignored because their were not:

worthy of being added to the Collective's perfection

What they are interested in, and what appears to be their own goal is:

the attainment of 'perfection' - Memory Alpha

Not only could assimilating the wrong species take away from the Borg's perfection but it certainly does not add to it. And the Borg are well aware that assimilating an entire species prevents it from further advancing and developing things that the Borg might value latter.


I have a theory (based on something Q said in "Q-Who," I think) that maybe there's something that could be holding the Borg back, prehaps an even greater threat that's never been revealed and the only reason Voyager never encoutered it was pure luck, I mean Q isn't exactly evil is he, he wanted to give the Enterprise a real scare and wouldn't have put them up against something that could destroy them in seconds. Note this is only a theory, but wouldn't it be a good basis for a film or something? Imagine Q pops up tell Picard and Janeway that the Borg have been utterly wiped out and totally exterminated and whatever, whoever did it, is heading straight for Earth?

  • 1
    Although at this point it would have to be an alternate timeline Picard and Janeway. And since its alternate we could even have Sisko join in too.
    – Xantec
    Commented Dec 7, 2011 at 19:30

Don't the Borg only assimilate life forms which are actually useful for them to assimilate. If a culture does not have anything worth looting they are not worth bothering with and just get ignored unless they pose a threat.


The Borg have always sought to advance themselves to a state of perfection as they see it. In Best of Both Worlds, when Picard is taken aboard the Borg Cube, the following exchange occurs (emphasis mine)

PICARD: I have nothing to say to you, and I will resist you with my last ounce of strength.

BORG: Strength is irrelevant. Resistance is futile. We wish to improve ourselves. We will add your biological and technological distinctiveness to our own. Your culture will adapt to service ours.

From Voyager, we learn that there are cultures the Borg would not assimilate and that they see the Omega Particle as almost divine.

Interestingly, some cultures were assimilated for specific purposes. For example, the Hazari in the Voyager episode Think Tank were said to make excellent tactical drones due to being technologically advanced and violent.

Essentially, it seems that a species had to have something to offer to be assimilated. Generally, this meant technology that The Collective did not possess already. That may be why the Kazon were unworthy of assimilation. They were fairly primitive and only had the technology they did because they took it from the Trabe relatively recently.

While the Kazon were an extreme example, the general idea on Voyager was that the Delta Quadrant was untamed and its people were unsophisticated. Voyager rarely encountered true equals and was generally vastly superior or inferior to the other species with whom they interacted, particularly early on.

As the ship got closer to Borg controlled space they encountered races that had been wiped out by the Borg such as species 116 and others who hid their technology to escape assimilation like the Brunali.

Other races may simply have been too powerful for the Borg to contend with openly in their current form (Species 8472 and the Voth). Based on every encounter with the Collective ever shown on screen, the Borg approach is to assume a position of superiority and dictate the situation to the betterment of the Collective. In situations where this was not possible, and failing an immediate solution, the Collective might back off until it was.

TL;DR Some races were unworthy of Borg attention, some were assimilated, some adapted to life near the collective, some posed too much of a threat for the collective to attack.


In "Parallels" a Captain Riker on an Enterprise D from an alternate universes says:

RIKER [on viewscreen]: We won't go back. You don't know what it's like in our universe. The Federation's gone, the Borg is everywhere! We're one of the last ships left. Please, you've got to help us!

It's not so bad in the main alternate universe, but to a lesser degree THE BORG ARE EVERYWHERE!!

Right, left, forward, back, up, down, the Borg are in every direction.

"The Neutral Zone"

DATA: Captain, there is nothing left of Outpost Delta Zero Five. LAFORGE: Must have been one hell of an explosion. DATA: Sensors indicate no evidence of conventional attack. PICARD: Can you determine what happened? WORF: The outpost was not just destroyed, it's as though some great force just scooped it off the face of the planet.

In "Q who?" Q sends the Enterprise over 7,000 light yeas through space in an unspecified direction.

DATA: According to these coordinates, we have travelled seven thousand light years

[Ten Forward]

DATA [OC]: And are located near the system J two five. RIKER: Travel time to the nearest starbase? DATA [OC]: At maximum warp, in two years, seven months, three days, eighteen hours we would reach Starbase one eight five.

Exploring a planet in system J two five they find:

WORF: Captain, the sixth planet in the system is Class M. DATA: There is a system of roads on this planet, which indicates a highly industrialised civilisation. But where there should be cities there are only great rips in the surface. WORF: It is as though some great force just scooped all the machine elements off the face of the planet. DATA: It is identical to what happened to the outposts along the Neutral Zone.

Then the Borg attack and they eventually have to ask Q to save them and send them back to where they were.

In "The Best of Both Worlds":

> Captain's log, Stardate 43989.1. The Enterprise has arrived at Jouret Four in response to a distress signal from one of the Federation's outermost colonies. [Transporter room]

RIKER: Anything from the surface? WORF: No sir. There have been no communications from the colony for over twelve hours. RIKER: Sensors picking up any signs of life? WORF: None. O'BRIEN: The surface environment is safe for transport, Commander.

[Planet surface]

RIKER: Mister O'Brien

[Transporter room]

RIKER [OC]: Verify these are accurate coordinates for New Providence colony. O'BRIEN: Coordinates verified, sir.

[Planet surface]

O'BRIEN [OC]: You're at the centre of town. (The centre of town is at the edge of a massive crater)

Captain's log, Stardate 43992.6. Admiral Hanson and Lieutenant Commander Shelby of Starfleet Tactical have arrived to review the disappearance of New Providence colony. No sign remains of the nine hundred inhabitants.

[Ready room]

HANSON: The truth is, hell, we are not ready. We've known they were coming for over a year. We've thrown every resource we have into this, but still RIKER: Then you're convinced it is the Borg? SHELBY: (blonde woman) That's what I'm here to find out. The initial descriptions of these surface conditions are almost identical to your reports from system J two five. PICARD: Commander Riker wrote those reports. He agrees with you.

HANSON: We expected much more lead time. Your encounter with the Borg was over seven thousand light years away. PICARD: If this is the Borg, it would indicate they have a source of power far superior to our own.

HELBY: The soil contains the same magnetic resonance traces That's our footprint. There's no doubt any more. It is the Borg.

Captain's log, stardate 43993.5. With confirmation of the Borg's presence in Federation space, Admiral Hanson has returned to Starbase three two four to discuss strategy with Starfleet Command. Lieutenant Commander Shelby remains on board to continue tactical preparations.

There are Borg at system J25 7,000 light years from Federation space, Borg at the Federation-Romulan Neutral Zone thousands of light years closer to earth, and now Borg in another section of Federation space. These three sets of Borg may belong to one, two, or three different Borg planetary colonies, ships, or fleets.

HANSON [on monitor]: We're coming with every available starship to assist, Captain, but the closest help is six days away.

So the nearest reinforcements are six days away, and no doubt Earth is even farther.

A Borg ship in the area near New Providence attacks the Enterprise, kidnaps Captain Picard, and leaves at warp speed:

WORF: Sir, the coordinates they have set, they're on a direct course to sector zero zero one. The Terran system. RIKER: Earth.

All during "The Best of Both Worlds Part 2" The Enterprise follows the Borg ship to Earth, and despite being delayed for eight to twelve hours to repair, eventually catch up with it. The Borg ship must travel no faster than The Enterprise and so should not have come from the area near system J25 7,000 light years from Earth but from a closer group of Borg.

As fans remember a federation fleet fights the Borg ship heading straight for Earth at the star system Wolf 359. Wolf 359 is one of the closest stars to earth, being 7.86 light years from Earth.

Wolf 359's coordinates in The equitorial system are right ascension 10 hours 56 minutes 28.99 seconds, declination plus 07 degrees 00 minutes 52.0 seconds.

Converting those coordinates into galactic coordinates using this site:


Gives the galactic coordinates of 306.5684° 69.8506°.

180 degrees of galactic longitude would be directly opposite the galactic center. 360 degrees would be right back at zero degrees and also pointed at the galactic center.

306.5684 degrees is pointed 53.4316 degrees from the galactic center. Earth is about 25,000 light years from the center of the galaxy and thus from the line separated the Alpha and Beta quadrants from the Gamma and Delta Quadrants.

A line from Earth at 45 degress from the galactic center would intercept the quadrant dividing line 25,000 light years from the galactic center and get farther and farther away from the galactic center as it got farther and farther into the Delta or Gamma Quadrant until it finally left the galactic disc, probably passing outside of Borg space even if it went through the Delta Quadrant and not the Gamma Quadrant.

And a line at 53.4316 degrees from the galactic center would pass through much less of the Gamma or Delta Quadrant than a line at 45 degrees from the Galactic Center.

The galactic latitude of 69.8506° for Wolf 359 is approximately 0.776117 of the 90 degree angle "up" from the galactic equator toward a vertical position "above" Earth. At such a steep angle the Borg ship would have crossed the galactic edge and the galactic barrier only about three to five thousand light years back on it's path - many fans would guess only about a thousand light years back.

if the Borg ship had come straight from the main body of Borg space in the galactic disc about 50,000 light years from Earth, it's trip toward Earth would be angled at a much "lower" galactic latitude.

The Borg already have colonies and fleets and single cubes at least 50,000 light years from the center of Borg space and the usual frontiers of Borg Space, and at least one such group is fairly close to Federation space.

Fortunately most of the Borg groups far from the center of Borg space are very widely and thinly scattered, and don't need to do a lot of assimilating. They spend much time studying each interstellar society or species they encounter, calculating the best time to assimilate it and waiting for decades, centuries, or millennia until they are ready to be harvested by the Borg. But every victim group will have their proper time.

So sooner or later everyone in Federation Space will have reason to sing:

The Borg are back and they're gonna make trouble,

Oh no! oh no! The Borg are Back!

The Borg are back and they're gonna smash Starfleet,

Oh no! oh no! The Borg are Back!

The Borg are back and they're gonna conquer Earth,

Oh no! oh no! The Borg are Back!

The Borg are back and they're gonna assimilate everybody,

Oh no! oh no! The Borg are Back!


  • 1
    OK, so why, if the Borg are so omnipresent, have they not assimilated everyone?
    – Adamant
    Commented Jan 2, 2017 at 5:14

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