Telos

The planet Telos was at one time the home of the Cryons. It was later colonized by the Cybermen and the location of the Cybertombs.

Characteristics
Following Cyberman occupation, Telos was a gray, barren, rocky world. Diamonds, vastial and other minerals could be found on the planet. (DW: Attack of the Cybermen)

History
At one time Cryons, who died instantly when exposed to temperatures above zero degrees, lived on Telos. The Cryons moved under the surface when it became too warm, constructing underground cities refrigerated to the zero temperatures the Cryons need to survive. The Cybermen later came to steal the referigerated cities to use as repositories of Cybermen cryogenically frozen in suspended animation. The Cybermen killed most of the Cryons. (DW: Attack of the Cybermen)


 * This was not the only planet on which the Cybermen left reserve armies, awaiting revival.

One thousand years after the last known encounter between Humanity and the Cybermen, an archaeological expedition from Earth, led by Kaftan and Klieg of the Brotherhood of Logicians landed on the planet to find the Cybermen and to revive them. With the Cybermen as their army, they planned to impose a regime of pure logic on Human society. The Cybermen were resurrected, and also their leader, the Cyber-Controller. The Doctor was able to seal them back inside their "tombs" and to electrify the outside gates. (DW: The Tomb of the Cybermen)

The Cyber-Controller was not, as the Doctor had believed killed, but survived, and had installed a base, known as Cyber-Control underground, supervising operations on 1985 London, with which they had a communications link and fighitng the Cryon rebels who remained. The Cybermen at this time employed work parties of Humans whose conversions were unsuccessful as slaves to mine the surface of the planet. The Cybermen intended to destroy Telos and to observe its blast pattern for future research. The base was, however, invaded and destroyed by the Doctor (now in his sixth incarnation). (DW: Attack of the Cybermen)