Attack on Voga

As recalled by the Fourth Doctor, the Cybermen waged a failed attack on Voga, either at "the end" of the Cyber-War (TV: Revenge of the Cybermen) or "after the end" of the Cyber-War. (PROSE: Doctor Who and the Revenge of the Cybermen)

By one account, the attack on Voga occurred in 2483 as part of the Galactic Cyberwars between the Earth Empire and the Cybermen, which eventually ended in 2489 with the defeat of the Cybermen. (PROSE: The Cyber Files)

Most of their ships vanishing after the attack, (PROSE: Doctor Who and the Revenge of the Cybermen) the Cybermen disappeared with humanity believing them to have died out. Centuries later, the CyberNomads made a second attempt to destroy Voga, but were defeat by the Doctor. (TV: Revenge of the Cybermen)