Cyber-Wars

The Cyber-Wars was a galactic conflict where a concerted effort united against the Cybermen in 2526 to wipe them out.The Cybermen tried to prevent this by destroying the Earth with a Cyber-Bomb and then by crashing a Human Freighter into the Earth, however both these attempts were stoped by the Doctor.(DW: Earthshock)

It was during this time that the glittergun was developed as a weapon against them. It would fire gold dust at Cybermen, gold being a major weakness to them. The Wars resulted in remnant groups of Cybermen fleeing across the galaxy. One group tried to destroy Voga, a planet of gold. (DW: Revenge of the Cybermen)