Hierarchy
Standing at the very top of the rigid Cyberman hierarchy, the Cyber-Controller oversaw Senior Leaders who commanded Major Phalanxes including Leaders, Junior Leaders and the Cyber-Army. (PROSE: Attack of the Cybermen)
History
In Pete's World, 2007, John Lumic led an army of Cybermen in an attempt to upgrade London. Though the army was destroyed by the Tenth Doctor more Cybermen produced by Cybus Industries existed across the world. (TV: The Age of Steel)
Following their defeat in the Great Cyber War, a Cyber-Leader led a Cyber-ship which, as it claimed, had enough parts to build an entirely new and invincible Cyber-Army, which was intended for a second campaign following the destruction of Voga. Ultimately, however, Voga was saved and the Cyber-ship was destroyed before the army could be created. (TV: Revenge of the Cybermen)
After another Cyber-War in the far future led to the fall of the Cyber-Empire, as well as the near-extinction of all humans in the galaxy, the human Ashad became the Lone Cyberman, and sought to recover the Cyberium from 1816, where it had been sent by the Alliance. (TV: Ascension of the Cybermen, The Timeless Children) He successfully brought it back to his time in order to rebuild the Cyber-Army and the Cyber-Empire. (TV: The Haunting of Villa Diodati) Using the Cyberium, he located a Cybercarrier containing an army of hundreds of thousands of Cyber-Warriors. However, his plot was ultimately foiled when the Spy Master killed Ashad to get the Cyberium for himself. The Cybercarrier was destroyed by Ko Sharmus, Ethan, Rovia and Yedlarmi using explosives planted throughout the ship, taking out the Cyber-Army onboard while most of it was still dormant. (TV: Ascension of the Cybermen, The Timeless Children)