The Cyber-Force, also known as the Cyber Empire, was the entire collaboration of forces of the Cybermen. It was composed of the Cyber-Fleets and the armies of Cybermen across the universe. The Cyber-Force was lead by the Cyber-Controller and a Cyber-Leader, assisted by a Cyber-Lieutenant.
They planned to use the Nemesis statue in 1988 to conquer Earth and make it into the New Mondas, their base planet. However, the Seventh Doctor used the Nemesis to destroy the entire Cyber-Fleet. (TV: Silver Nemesis).