After two failed invasions of Earth, the Borg diminished as a threat to the Federation throughout
the 2370s, due to a series of catastrophes in the Delta Quadrant which forced them to
focus on securing their own space.
Though they continued to engage in occasional battles against the Federation within the
Alpha and Beta Quadrants, they endured their greatest struggles in their fight against
the USS Voyager, a lone Starfleet ship pulled into the Delta Quadrant in 2371 by the Caretaker,
a powerful being searching the galaxy for a compatible mate.
When the Caretaker died and his technology was destroyed, Captain Janeway and the Voyager
crew had no choice but to make the long, 70,000 lightyear journey back to Federation space.
A task they believed could take up to 70 years and which eventually required them to pass
through Borg space.
After discovering the Sakari, a species nearly annihilated by the Collective, Voyager had
their first encounter with the Borg in 2373, when they identified a non-functional Cube
while travelling through the Nekrid Expanse.
Sending their people aboard the ship, Voyager took the opportunity to learn all they could
about their enemy’s advanced technology and soon uncovered that some of the Borg survived
the electro kinetic storm which damaged the Cube in 2368.
Yet much to their surprise, the accident severed the link between these drones and the hive
mind, allowing them to gradually reclaim their individuality and former appearances, using
salvaged Borg technology to remove many of their implants.
Making their home on a nearby planet, these former drones eventually divided into factions
and went to war over resources, leading a few hundred to create a cooperative, where
they promoted peace and equality while defending themselves from the more aggressive groups.
Hoping to end the fighting on their world, the Cooperative planned to reactivate the
neural electric generator onboard the damaged Cube, thereby allowing those on the planet
to share thoughts in a new Hive Mind, separate from that of the larger Collective.
Unable to enact this plan themselves, they found their opportunity after rescuing Voyager’s
first officer Chakotay, who was attacked by a violent faction shortly after landing on
their planet.
Using a neural transceiver to link their minds to the First Officer, the Cooperative healed
his wounds but also gained access to his thoughts, allowing them to temporarily take control
over his mind.
Although they attempted to ask for Voyager assistance, Janeway denied their request,
and so they used their link to force Chakotay to board the Cube and reactivate the generator.
With the new Hive Mind established, they made peace among the factions, released Chakotay
from their control, destroyed the Borg Cube and apologized to Voyage for their actions,
claiming it was necessary for their survival.
Continuing their journey to the Alpha Quadrant, Voyager soon entered into Borg Space where
they found that an even greater threat was wreaking havoc throughout the Collective.
The trouble began when the Borg discovered Fluidic Space, an extra-dimensional realm
where they found Species 8472, beings whose physiology they described as the Apex of Biological
Evolution.
Breaking through the dimensional barrier, the Borg sought their assimilation but were
quickly outmatched and defeated.
In response to this invasion, Species 8472 retaliated by attacking the Delta Quadrant,
where they sought to exterminate all life.
In addition to possessing heavily armoured, warp capable organic ships, operated by a
single pilot, Species 8472 were telepathic, up to 3 meters tall, physically powerful,
did not require sleep, could survive in the vacuum of space, produced a biogenic field
protecting them from sensors, could infect enemies with cells that consumed them from
inside and had an immune system which destroyed nearly any foreign substance, making them
resistant to nanoprobes and assimilation.
Fighting a vicious war from 2373-2374, the Borg suffered massive casualties, losing ships,
planets and entire systems until forming an alliance with the USS Voyager, whose Doctor
discovered a way to modify nanoprobes, thereby neutralizing the infectious cells of species
8347.
Promising to aid the Borg in exchange for safe passage through their Space, Voyage worked
with the Collective for a time, creating weapons and defenses to use against their common foe.
In order to facilitate communication between them, the Borg selected the drone 7 of 9,
tertiary adjunct of Unimatrix 01, as their representative, eventually sending her to
work aboard the Federation ship.
In the end, Voyager’s new nanoprobe technology allowed the Borg to defeat Species 8472, forcing
their bioships back into Fluidic Space.
With the war over, the Borg attempted to turn against Voyager, but they anticipated this
betrayal, and incapacitated Seven of Nine, cutting off her connection to the Hive Mind
which allowed them to escape and continue on their journey.
Free from the Collective, Seven of Nine slowly regained her individuality and became a prominent
member of the crew.
And while the Borg made a number of attempts to get her back, their efforts ultimately
failed.
With Seven of Nine acting as a bountiful resource for information about the Collective, Voyager
learned much about these cybernetic beings, including their interest in the Omega Molecule,
an unstable molecule described as the most powerful substance in existence.
With a single molecule possessing the energy of warp core, while a chain of them could
power an entire civilization.
The Borg first learned about, what they called Particle010, in 2145 through the assimilation
of 13 species, and after much experimentation were able to synthesize and stabilize a single
molecule for 1 trillionth of a nanosecond, before it detonated.
In total, the Borg lost 29 vessels and 600 000 drones to these experiments before they
ran out of material to synthesize more.
Yet in spite of their losses, they were so impressed by the substance they sought to
assimilate any information possible, believing it existed in a flawless state, infinitely
complex yet harmonious and therefore represented perfection.
Therefore when Voyage came across the wreckage of another civilization in 2374, who were
conducting their own experiment with Omega, Seven of Nine demonstrated a profound reverence
for the molecule, comparing her feelings to that of religious worship.
In the years that followed, as Seven’s personality continued to emerge and develop, she became
a mentor to a number of former Borg Drones encountered by Voyager, teaching them to reclaim
or foster individual identities.
Her first student emerged in 2375, when a transporter malfunction incorporated Seven’s
Borg nanoprobes into the Doctor’s mobile holoemitter.
Using the holoemitter’s , 29th century technology acquired during a mission involving a timeship
from the future, the nanoprobes built a maturation chamber, extracted DNA from a voyager Ensign
and created a powerful new lifeform, which in essence was a 29th century Borg.
Hoping to use this advanced being to defend them against the Collective, Janeway allowed
the fetus to develop, entrusting his development and education to Seven of Nine.
Developing 25 times faster than a normal Drone, the fetus quickly became a full grown adult
male who chose the name One, and with Seven’s help, was accepted as a member of the crew.
Yet in spite of disconnecting his link to the Hive Mind, his advanced technology allowed
for a secondary neural transceiver to emerge which inadvertently contacted the collective.
Coming under threat from a Borg Sphere, One upgraded Voyager’s shields and phasers,
but it was not enough, and so he transported onto the enemy ship, destroying it from within.
Recovering his body, Voyager’s doctor attempted to heal the damage to his organic parts, but
One now understood the Collective would never stop pursuing him, and so chose death in order
to protect Voyager.
In 2376, Seven of Nine once again became a mentor to a group of Borg Children rescued
from a damaged cube, becoming a mother figure to them as they regained their individuality.
Although they eventually found a home for the 3 youngest children, the eldest boy Icheb
became a permanent member of the crew.