Cyberman invasion of Earth (The Invasion)

The Cyberman invasion of Earth, known by the Cyber-Planner as the Cyber-invasion, was an attempted invasion of Earth by the Cybermen in the late 20th century. (TV: The Invasion) It was the first invasion of Earth by the Cybermen recorded both in the history computer of the CyberFaction (PROSE: Iceberg) and in the Cyber-Documents of Earth, which were compiled into the CyberHive by the ArcHivist Hegelia. (AUDIO: The Early Cybermen)

Besides the involvement of the Cybermen, the invasion was notable for marking the second encounter between the Doctor, then in their second incarnation, and Alistair Gordon Lethbridge-Stewart, as well as the newly formed UNIT's first dispatching of a major alien incursion. (TV: The Invasion)

Date
The invasion occured four years following the London Event (PROSE: Downtime, TV: TV: The Invasion) According to the Hegelia, the invasion took place some time in the 1970s, (AUDIO: The Early Cybermen) possibly the year 1970. (PROSE: Killing Ground)

Cyber-activity
As recorded in the CyberHive, the Cybermen who were to wage the "first invasion" were of the "early CyberFaction", descended from the original CyberMondasians. Unlike their fellow Mondasians, who performed only the essential bodily modifcations needed to preserve their endangered lives, this CyberFaction fully embraced cyber-conversion and ultimately left their home planet of Mondas. Taking off into outer space, these Cybermen established a base on Planet 14. (AUDIO: The Early Cybermen, PROSE: Iceberg) At some point, the Second Doctor and his companion Jamie McCrimmon appeared on Planet 14, and were from then on recognised as a danger by the CyberFaction. (TV: The Invasion)

According to another account, Mondas and Planet 14 were one and the same planet, originally known as Marinus. As it turned out, the planet had been visited by the Sixth Doctor and an elderly Jamie, long after defeating the invasion from their perspectives. There, they witnessed the genesis of the Cybermen as the Voord converted themselves into what resembled the early CyberFaction. Ultimately, the Doctor was denied the opportunity to prevent the rise of the Cybermen by the Time Lords. (COMIC: The World Shapers) Later, however, the Twelfth Doctor cited Mondas, Planet 14 and Marinus seperately amongst the places where the Cybermen begun as a result of parallel evolution. (TV: The Doctor Falls)

A force of Cybermen from the 30th century travelled back in time to Jersey in 1939, fleeing to mainland Britain when the Nazi German forces invaded the following year. The Cybermen left behind a sleeper force in the Le Mur Engineering factory, which the Nazis began studying. The fleeing Cybermen set up a new base of operations in the Peddler Electronic Engineering factory in London. In November 1940, the Cyber-Leader which led the group of Cybermen away from the Channel Islands was damaged by a bomb and went mad, committing a series of murders around London's East End to sustain itself. The Seventh Doctor used the Blitz to destroy this force of Cybermen by lighting up the Peddler Electronic Engineering factory, making it an easy target for the Luftwaffe. The following day, the Doctor travelled to Jersey to destroy the remaining Cybermen in the Le Mur compound and put an end to the Nazi research. After the Doctor departed, Patrick Mullen and Cody McBride discovered a third, much larger dormant Cyberman army hiding in the London sewers beneath London in preparation for a later invasion. (PROSE: Illegal Alien)

UNIT
Four years prior to the Cybermen's "first invasion" was the London Event, an attempted invasion of Earth by Robot Yeti controlled by the Great Intelligence, based in the city of London. This attack opposed by a British Army forced led by Colonel Alistair Gordon Lethbridge-Stewart, and ultimately defeated with the assistance of the Second Doctor and Jamie McCrimmon. (PROSE: Downtime, TV: The Web of Fear) Following this incident, the United Nations Intelligence Taskforce, simply known as UNIT, was formed to tackle alien threats to Earth. (TV: The Invasion, Spearhead from Space)

The invasion
to be added

Aftermath
Bits and pieces of damaged Cybermen remained in the London sewers. One Cyberman managed to cannibalise garbage it found in the sewers to repair itself and create a considerable amount of Cybermats. The Third Doctor and Jo Grant stopped it from infecting an entire hospital with cybermites. (PROSE: The Piper) In 1975, two Cyberman heads were found in the sewers; one was sent to the Leamington Spa Lifeboat Museum (GAME: Security Bot) while the other head would eventually end up in Henry van Statten's Vault. (TV: Dalek)

UNIT kept at least two Cyberman heads from this invasion, one of which was stored at the Underbase. (TV: Death in Heaven, COMIC: The Age of Ice)

Some Cybermen survived the destruction of the invasion fleet. Many were propelled into deep space. One Cybership crashed in Antarctica, where it remained frozen and hidden for two decades. (PROSE: Iceberg) Another Cybership managed to escape back to Isos II. The Second Doctor, Jamie McCrimmon, and Zoe Heriot followed the ship and destroyed all traces of the Cybermen on Isos II. (AUDIO: The Isos Network)

Vaughn survived his apparent death by transmitting his mind into a robotic copy of himself created with cybertechnology. For many centuries, Vaughn continued to influence Earth while repairing his robotic body with parts salvaged from failed Cyberman attacks on humanity. (PROSE: Original Sin, AUDIO: Original Sin)

During his trial by the Time Lords, the Second Doctor, speaking in defense of his violations of the non-interference policy, cited the Cybermen as an example of the evil he fought against, describing them as "half creature, half machine" species whom attempted to conquer the Earth. Via a Thought Channel, the Doctor projected the image of a "early CyberFaction" Cyberman, the type which waged the first invasion. Considering the Doctor's plea, the Time Lords sentenced him to exile on Earth in the 20th century with a forced regeneration. (TV: The War Games)

Some months after the Cyberman invasion, (TV: Planet of the Spiders) the newly regenerated Third Doctor appeared on Earth, the secret of how to operate the TARDIS lost to him. Meeting the Brigadier once again, the Doctor was employed by UNIT as a scientific adviser, assisting them with numerous alien incursions. (TV: Spearhead from Space) Eventually, at a point some years after the invasion, the First Omega Crisis forced the Time Lords to extract the Second Doctor from his time stream to assist the Third Doctor in combating Omega. As a result, he was reunited with the Brigadier and Benton, explaining that he was indeed an earlier version of the Doctor they were presently associated with. Ultimately, having been saved from Omega thanks to their help, the Time Lords returned the ability to operate the TARDIS to the Third Doctor. (TV: The Three Doctors)

Later still, at a UNIT reunion, the Second Doctor and the Brigadier reminisced about the Yeti, the Cybermen and Omega, with the Brigadier observing that they had "seen some times". (TV: The Five Doctors)