The Cybermen that appeared in the original Doctor Who series were the Mondas Cybermen, they once were human beings living in Earth's twin planet of Mondas. When their planet drifted away into space they soon replaced their limbs with stronger metal ones to survive, removing their emotions to make them stronger and through time they became Cyermen, after Mondas was destroyed they swarmed across the galaxy like a plague.
The Cybermen that appeared in series 2 of new Doctor Who and onwards are mainly known as Cybus Cybermen that were created by John Lumic from a another Universe, a parallel world similar to the Doctor's world.
Mondas CybermenIn the first appearance of the cybermen they plan to modify humanity to make it the new cyber age, and plan to bring their planet "Mondas" to crash into Earth, but their plan is foiled by the doctor who uses a rocket to destroy Mondas, but not before killing the Doctor causing him to regenerate.
Their armor and technology was basic at first, but as the series progressed they became more deadly and would travel the universe converting other humanoid beings into their increasing army.
In the 2nd appearance of the Cybermen, they attempt to use a deadly mind controlling disease to take over the moon base and earth. They were almost successful until being defeated by the Doctor and his companions. The remaining Cybermen were destroyed. Although other Cybermen on different locations were still alive, including a small group of Cybermen as well as the smaller Cybermats, stationed on Telos in hibernation, they were protecting the first Cybercontroller any were accidentally brought back out of hibernation by the Second Doctor and a group of explorers however they were eventually all defeated when the doctor refreezes the tomb.
From the mid 1970s through 1985, Cybermen lurked in the sewers below London, awaiting another invasion. This would happen in December 1986. However the first Doctor would stop them, although it resulted in his death and forced him to regenarate. Mondas was destroyed in the attack as it absorbed too much energy and exploded.Before the invasion, having captured a time vessel, the Cybermen knew that the First Doctor would eventually destroy Mondas. They planned to divert Halley's Comet towards Earth in 1985. They hoped the destruction of Earth would change the past so Mondas would survive. The Sixth Doctor foiled them.
Needing a new homeworld, the Cybermen battled against the Cryons who lived on the icy world of Telos, the Cybermen hoped to take over the planet and preserve themselves in ice. Although the Doctor would stop them.
Some Cybermen were part of the death games on Gallifrey. They formed a alliance with the Doctor's rival known as the Master another Time Lord.
The Mondas Cybermen would make their final debut in "Silver Nemises" In November 1988, a scouting party was sent to Earth in search of a statue made of validium called Nemesis, a Time Lord weapon. The Cybermen met Lady Peinforte, who brought many of their number down with gold-tipped arrows. Although many survived.
In the vault of billionare Harry Van Statten, a head of a Mondas Cyberman was seen on display. On its case it said it was recovered from the sewers of London in 1975.
When the Tenth Doctor accidently arrived on Pete's World, a parellel universe to the Doctor's world. He and his companions encountered this universe versions of the Cybermen. The Doctor told his companion Rose that the Mondas are still alive in their universe.
Cybermen of Pete's WorldThe Cybermen of the parallel world, nicknamed "Pete's World" were created and designed by dying business tycoon John Lumic who was in charge of Cybus industries.
Lumic wished to create the next level of mankind so humans could live forever. Lumic would remove all human emotions making them stronger, and the human brain would be placed into a disease free almost indestructible cybernetic body. The brain soaked with chemicals and all emotions removed would make them powerful.
Lumic called this the ultimate upgrade. The new Cybermen seemed to be heavier and stronger than the Mondas Cybermen.
However, the President of Great Britain refused to allow people to be upgraded. Although Lumic went ahead with his plan by kidnapping homeless people and upgrading them into Cybermen.
Using the EarPods he designed and sold out to most of the population of Great Britain, Lumic took mental control of the people of London, marching thousands to be cyber-converted. After his life-support systems were damaged by his assistant, Mr. Crane, Lumic was converted into the Cyber-Controller. However, the Tenth Doctor and his companions, having accidentally landed on the parallel Earth, managed to foil his plans. They freed London from mental control and disabled the Cybermen's emotional inhibitors, causing them to go insane and in some cases explode. Lumic himself fell to his apparent death into the burning remains of his factory. A human resistance group, the Preachers, then set about to clean up the remainder of Lumic's factories around the world.
The Preachers first made an attack on Paris, France. Where another Cyber Factory was located and battled the Cybermen. Mickey Smith used the captured Cyber zeppelin to fight the Cybermen and helped defeat them.
Cybermen on other countries were sealed inside their factories, and a debate went on discussing what should be done with them. Then suddenly the Cybermen, which numbered in five million simply vanished. They had crossed the void which was between worlds, and entered the real world, the Doctor's universe.
At first they appeared like ghosts which the people of Earth thought was their dead loved ones, they established a base inside the Torchwood Tower at Canary Wharf. While there, they started making new Cybermen, using what materials they could find. After two months (three years in parallel Earth time), the Cybermen suddenly appeared in their true form, occupying every landmass on the planet before breaking into houses and promising to upgrade all humans, commanded by the new Cyber-Leader.
They told the Doctor that they crossed between worlds, by following a void ship which broke down the barriers between universes. The void ship they followed was revealed to be of Dalek origins and four Daleks known as the Cult of Skaro emerged from the ship along with the genesis ark.
When Dalek Thay of the cult encountered two Cybermen, the Cybermen at first thought they should join each other and upgrade the universe and Dalek Thay declined the request. The two Cybermen tried to delete Thay, but the Dalek simply exterminated them.
The Cyber Leader declared war upon the Daleks, although the Cult's leader Dalek Sec saw the Cybermen as weak. After a skirmish between humans, Cybermen and Daleks, the Cult traveled to the main room in Torchwood's Canary Wharf, elevated outside above the roof, and opened the Genesis Ark, releasing millions of Daleks who, under Sec's command, started to "exterminate all life-forms below", killing human and Cyberman alike.
The Cybermen's laser weapons and advanced guns could not kill the Daleks, while one shot from a Dalek's gunstick could kill a Cybermen instantly.
The Cyber leader realized that too many Cybermen were being destroyed by the Daleks, and ordered other Cybermen in London to go to Torchwood and fight the Daleks, although many would be destroyed. Towards the end of the Cybermen-Dalek battle, the Cybermen, desperate for more troops, began directly converting people rather than transplanting their brains into Cybershells. One victim of this process was Lisa Hallett, girlfriend of Ianto Jones.
The Tenth Doctor and Rose Tyler opened the Void and anything contaminated with void stuff was pulled in. This included the Cybermen. Although Dalek Sec and the rest of the Cult escaped with Emergency Temporal shift.