A Cyber-Lieutenant served under a Cyber-Leader in an attempt by some CyberNeomorphs in 1985 to destroy Earth before humanity could destroy Mondas in 1986.
The Cyber-Lieutenant served in the Cybermen's base in the London sewers and also acted as the Cyber-Controller's adviser and reporter. The Lieutenant also advised the Cyber-Leader not to trust Lytton. (TV: Attack of the Cybermen)