The Void

The Void was what the Time Lords called the emptiness found between all parallel universes, different dimensions, and other realities. (TV: Army of Ghosts)

The Void was often used as a place of banishment for destructive or dangerous beings exiled from their home universes. These included, at various times, beings native to the Doctor's universe &mdash; including armies of Daleks (TV: Doomsday, Revolution of the Daleks) and the Osiran deity Sutekh (COMIC: Old Girl) &mdash; and beings from "outside" that universe, such as Sunyata, (PROSE: Night of the Intelligence) the Cybermen of a parallel world, (TV: Doomsday, The Next Doctor) the King Nocturne, the Dragon, one of the Gods of Ragnarok, (COMIC: Old Girl) and Lord Thymon, a time-demon who later reformed. (PROSE: Auteur's Abecedarium) In addition, the Division's Control ship was located in the space between universes, which allowed Tecteun to attempt to destroy the universe with impunity. (TV: Survivors of the Flux)

Nature
The Void existed beyond the edge of the universe. (COMIC: Voyager) The Book of the War stated "immeasurable stretches of un-space" separated different universes but also claimed it was "apparently impossible" to cross those "un-space gaps". (PROSE: The Book of the War) Many accounts showed it was indeed possible, (TV: Army of Ghosts, et. al) but not always easy, (TV: Rise of the Cybermen) to cross through the Void.

The Void contained no light nor darkness. It also featured no temporal or spatial dimensions (neither "up" nor "down"), but the Tenth Doctor used some spatial language to conceptualise how the Void was "in between" all the universes which were "stacked up against each other". Even time in most senses did not actually exist there. Anyone who entered the Void could choose to let eternity pass them by: they would "exist outside the whole of creation" and would be completely unaffected by events as major as the end of their home universe or the start of another. (TV: Army of Ghosts)

The Void could be also be used to achieve a form of time travel that operated on principles completely unknown to the Time Lords. Completely bypassing the Time Vortex, this required astronomical amounts of energy to perform when compared to Vortex-based travel. (AUDIO: Homecoming)

A Void Ship was a spaceship which could enter, traverse, and exit the Void into other dimensions due to being constructed so as not to really exist within its original reality. Even the Time Lords, (TV: Army of Ghosts) whose TARDISes were nevertheless occasionally capable of traversing dimensions, (TV: Rise of the Cybermen) believed such a vessel to be a theoretical concept only, impossible to build in their reality. They were proven wrong by the Cult of Skaro during the Last Great Time War. (TV: Army of Ghosts) All material which travelled through the Void absorbed a particular type of harmless background radiation, which the Doctor called Void stuff. The longer a material had been present within the Void, the more "Void stuff" it became saturated with. (TV: Doomsday)

The space between dimensions was timeless. As a result, while still conscious, a living being trapped in that space would see their metabolism frozen, making them functionally immortal. (PROSE: Preternatural Nights)

Native life
The Tenth Doctor asserted that no life existed naturally inside the Void. (TV: Army of Ghosts) However, the Twelfth Doctor discovered that the Fractures were beings that lived inside the Void, and compared them to antibodies for the multiverse. (COMIC: The Fractures)

Chronomites naturally traversed space-time "riptides" and the Void. (GAME: TARDIS)

According to ancient Gallifreyan myth, the Mi'en Kalarash inhabited "the wasteland between realities". (AUDIO: House of Blue Fire) The Terrordactyls were native to the "Great Space-Time Void". (GAME: The First Adventure)

Intercreationals such as Leviathans and Swimmers lived in the Void. (PROSE: The Book of the War)

Ancient history
Before the universe, the Champion of Neutrality locked himself, the Guardian of Might and the Guardian of Magic in the Druse, which he excised from the universe and placed in the void between worlds. However, it remained connected to the universe through small "cracks" and the three entities' dreams eventually drifted into the minds of humanity. (PROSE: Legends of Camelot)

One of Rassilon's titles was "Ravager of the Void". (AUDIO: Neverland) According to one account, Sunyata resided in the Void, and manifested inside the universe as various avatars of the Great Intelligence. (PROSE: Night of the Intelligence) The Celestial Toyroom existed somewhere in the Void. (TV: The Celestial Toymaker)

In the earliest days of TARDIS technology, a prototype Type 1 TARDIS malfunctioned and ended up in the Void. Content with the peace, it had no desire to return to the Doctor's universe, prompting the Eleventh Doctor to share his memories of the universe with her to convince her to return home. Finding the universe to be a chaotic place, the Type 1 used the Void to attack reality, opening white holes that drew the universe into her. When the the Doctor's other incarnations were drawn into the Void they linked their TARDISes to the Type 1, convincing it to jettison all it had swallowed. Though the Eleventh Doctor was rescued by his other selves, the Type 1 elected to remain in the Void, enjoying the quiet. (COMIC: The Lost Dimension)

Under the Time Lords
While the Time Lords ruled the universe, it was relatively easy for them and their agents to cross between dimensions. (TV: Rise of the Cybermen) Later TARDIS models were able to traverse the boundaries of the universe, enter the "eternal nothingness", and return, without incident. (PROSE: Cat's Cradle: Witch Mark)

When crossing from his world to that of the "Inferno Earth", the Third Doctor briefly experienced passing through what he described as "a sort of limbo". (TV: Inferno) The Fifth Doctor and Nyssa became trapped in the "dimensional interface," the "space between worlds" after escaping a collapsing time bubble, but later broke free. (AUDIO: The Eternal Summer)

After being trapped by the Fourth Doctor in a reprogrammed time corridor meant to age him to death, Sutekh made use of an escape hatch to which he had earlier availed himself, "stepping sideways" into the Void. He was trapped there with countless other gods originating from other realities. Some had come there of their own accord to wait out eternities, but others were trapped. Of those, many, such as one of the Gods of Ragnarok, had previously tried to take the Doctor's universe but been foiled by the Doctor; they thirsted for revenge and tried to bargain with Sutekh. They knew that, being native to the Doctor's universe, he would one day be able to return there, and begged him to help them cross over as well when he did, promising him their allegiance. (COMIC: Old Girl)

The Sixth Doctor witnessed Voyager sailing his death-ship off the edge of the universe and into the Void beyond. He was stopped from falling off the edge himself by Frobisher, who, his perspective bound by logic, could not see the edge and thought he had merely saved the Doctor from falling into the sea. (COMIC: Voyager)

The Eighth Doctor's attempted to alter the unstable alternate timeline created by his TARDIS' crash landing in 2020, he destabilised reality allowing the Void to encroach in the universe. The Void was held back by the Curator long enough for the Doctor to depart, averting the changes to the timeline. (AUDIO: Crossed Lines) When another attempt of the Doctor's to change history went awry, the Void consumed the entire alternate timeline leaving only 107 Baker Street, which it too began to consume. Eventually all that was left was a reinforced portion of the attic, designed by the Curator who left the Eighth Doctor and Robin Bright-Thompson there to give them time. The pair were retrieved from the Void by Liv Chenka, Helen Sinclair, Andy Davidson and Tania Bell. (AUDIO: The Keys of Baker Street)

During the Time War
Durring the course of the Time War, the Void was targeted by the Daleks, who developed technology allowing them to use the Void as an alternative to the Time Vortex and achieve their own independently created method of time travel. This exploit became unusable after the detonation of a resistence weapons cache and modified Battle TARDIS effectivly 'poisoned' the well and prevented the functionality of the Dalek Null Drive. (AUDIO: Homecoming)

Pessimistic about the outcome of the Last Great Time War, the Cult of Skaro decided to ensure the Dalek race's survival by escaping into the Void using the Sphere, a Void Ship of their own design, and waiting out the rest of the War from its confines. Within it, they carried the Genesis Ark, a prison ship they had stolen from the Time Lords, which contained millions of trapped Daleks. (TV: Doomsday)

Thanks to the final battle of the War, the Dalek Emperor and his flagship tumbled through time (TV: The Parting of the Ways) and the Void, (PROSE: The Whoniverse) ending up around the era of the Fourth Great and Bountiful Human Empire. (TV: The Parting of the Ways)

Consequences of War
Failing to escape the Council of Eight in the aftermath of the War in Heaven, (PROSE: Anachrophobia) the Clock-People were banished into the Void Between Worlds. However, they managed to reenter the universe using "the dreams of a little girl". (PROSE: Out of the Box)

The Ninth Doctor jettisoned the Matryoshka drive powering Hesguard Institute into the Void, in order to put a stop to the use, and subsequent uprising, of Sin-Eaters on criminals. (COMIC: Sin-Eaters)

In 2007, to his dismay, the Tenth Doctor identified the object around which Torchwood Tower had been constructed as a Void Ship, and explained its significance to the befuddled human scientists. Soon it was discovered that this mysterious bronze sphere was the Cult of Skaro's Void Ship, with the Cult exiting it triumphantly.

As it returned to the universe, the Cult's Void Ship created a breach between the Doctor's universe and an adjacent parallel universe, causing them to "collide" into each other. (TV: Army of Ghosts) Falling through this gap in the Space-Time Vortex, the Doctor's TARDIS was able to crash-land in the parallel universe, which the Doctor would later label Pete's World. (TV: Rise of the Cybermen)

Some time later, Pete's World's Cybermen took notice of the "wake" of the Daleks' sphere and used it to cross over to the Doctor's universe, hoping to convert its human population on top of that of their own world. (TV: Army of Ghosts)

As the Dalek force, freed from the Genesis Ark, began to exterminate the Cybermen army in the Battle of Canary Wharf, the Tenth Doctor widened only one side of the Void breach. Since they were saturated in Void stuff, all of the Cybermen and all but 4 of the Daleks were sucked back into it. The breach then permanently sealed itself. (TV: Doomsday) The four Daleks of the Cult of Skaro escaped being hurled into the Void by means of an emergency temporal shift to Manhattan in 1930. (TV: Daleks in Manhattan)

In 2008, Cybermen survivors of the Battle of Canary Wharf who hadn't been sucked into the Void as they were cyber-converted during the battle attempted to force the Doctor to reopen the Void and release the Cybermen trapped inside. The Doctor insisted that he was unable to do so, leading to a Cybermen attack on a military base. However, the military repelled the attack, killing most of the Cybermen who kidnapped Martha Jones and held her hostage at the Millennium Dome to force the Doctor's compliance. The Doctor feigned compliance, but in actuality opened a space-time portal to the Jurassic era rather than a portal to the Void. A T-rex that came through the portal briefly destroyed two of the remaining Cybermen while the Doctor destroyed their leader, foiling the plot. (PROSE: Made of Steel)

Trapped in the Void, the Pete's World Cybermen stole or scavenged two things from the Daleks who were trapped with them: intelligence about the Doctor, and a Dimension Vault. Although the Doctor believed that the tests of the New Dalek Empire's reality bomb caused all living things within the Void to die, he discovered some of the Pete's World Cybermen back in the Doctor's universe; he theorised that they had been ejected from the Void beforehand through some sort of rift. They were able to use the Dimension Vault to travel to 1851 London, where they built a CyberKing. (TV: The Next Doctor)

Gods and monsters in the Void
Adam Smith, (TV: Adam) a Memeovore, (AUDIO: Madam, I'm) claimed to Torchwood Three that he had escaped from the Void. (TV: Adam)

Sutekh, still trapped in the Void, was joined in his banishment by the King Nocturne, (COMIC: Old Girl) a conceptual entity whose quantum make-up the Tenth Doctor had managed to destabilise, (COMIC: The Jazz Monster) as well as by the Destroyer, (COMIC: Old Girl) a demon whose physical form had been destroyed by Alistair Gordon Lethbridge-Stewart in Arthur's World. (TV: Battlefield)

Eventually, Anubekh, a splinter of Sutekh's consciousness whom he had left inside the Hand of Sutekh in case he should be banished from the world, awoke and possessed Sutekh's son Anubis. Anubekh was able to take control of the Circle of Transcendence and release Sutekh, and several of the gods with whom he had allied himself, from the Void. Sutekh sought to prevent the Doctor from sucking him back into the Void by "plugging" the Circle of Transcendence with the Destroyer, but was, before long, forced back into the Void by his own Hand of Sutekh, who had, unbeknownst to him, merged with the consciousness of the selfless human Dorothy Bell. In the process, Bell herself became trapped in the Void, sacrificing her freedom to prevent the Doctor from making this same sacrifice in her place. (COMIC: Old Girl)

After failing to invade Gallifraxion Four and being placed on trial, the Greth was condemned by Carvil the Resurrected, the leader of the Clock-People, to banishment in the Void Between Worlds. There, it made contact with a force from the days before History, which helped it return to the universe, reemerging in the Infernal Depths on Earth, after making a deal with it. (PROSE: Out of the Box) In 2018, after Archie MacTavish fell through a dimensional tear, (AUDIO: What Happened in Manchester) he found himself frozen in the timeless space between dimensions, gazing out into the next universe, a world of darkness that was home to the Yssgaroth; it made a deal with him as well. (PROSE: Preternatural Nights)

Further adventures of the Doctor
When the Eleventh Doctor was, for a time, erased from existence by stepping into the cracks, River Song described him as being condemned to the never-space, the Void between worlds. (TV: The Big Bang)

To defeat the Death Squad Daleks the Thirteenth Doctor tricked them into entering a "spare" TARDIS, that she had programmed to crumble in on itself and go to the "heart of the Void". (TV: Revolution of the Daleks)

Behind the scenes

 * Before making use of "the Void" in his script for TV: Army of Ghosts, Russell T Davies had mentioned an Ultimate Void, located "beyond the Time Vortex", as one of the battlefields of the War in PROSE: Meet the Doctor. Although it is more likely than not that he loosely intended for the two Voids to be one and the same, no valid source has ever confirmed the link.
 * Although metaphysically questionable, the concept of a Void Between Worlds is far from being unique to Doctor Who, instead being a staple of science-fiction and fantasy works involving a multiverse or omniverse, as is the idea of various horrors being exiled there and trying to make their way back into "our" world.
 * Explaining how Henry van Statten was unfamiliar with the Dalek he named Metaltron, The Time Traveller's Almanac suggested that the Van Statten Incident took place in a timeline where the Cult of Skaro were still inside the Sphere within the Void, yet to emerge in Torchwood London and precipitate the Battle of Canary Wharf in 2007 and so did not go on to influence the construction of the Empire State Building, nor was the Earth transported to the Medusa Cascade since the personal timelines of both the Doctor and the Dalek race had not progressed to the point where those events occurred.

Le Void