In 1988, though it may have done so through time travel, a Cyber-Fleet consisting of thousands of Cyber-Warships came to Earth seeking the Statue of Nemesis. With it, the Cyber-Leader planned to conquer the Earth and make it their base planet as the New Mondas, turning all humans into slaves.
When confronted by the Cybermen, the Seventh Doctor surrendered the Nemesis to them and launched the statue on the rocket-sled to meet with the Fleet as the Leader instructed. When the Nemesis reached the fleet in orbit of the Moon, having understood the Cyber-Leader's instructions and disobeying them, it exploded, destroying the entire Cyber-Fleet. (TV: Silver Nemesis)
In 1992, a fleet hid beneath the Atlantic Ocean and attempted to conquer Earth, but were destroyed by the Sixth Doctor turning the Cybermen's dehydration weapons against them. (AUDIO: Hour of the Cybermen)
On 5 December 2021, a Cyber-Fleet of Cyber-Warriors, composed of the amassed Cyber-battalions, joined with the Dalek War Fleet as both factions accepted the Sontarans' deceitful offer of protection against the final Flux event. When the Sontarans released the Lupari shield, both fleets were destroyed. (TV: The Vanquishers)
The fleet was possibly destroyed during the Cyber-Wars, with the remnant Cyberman groups scattered across the Mutter's Spiral, forced to use ancient cyber-ships for travel. (TV: Revenge of the Cybermen)
At the end of the universe, upon forming an alliance with Rassilon, the Cyberiad provided the disgraced Time Lord with the Gallifreyan Cyber Fleet which was used to quickly conquer Gallifrey. When the Cybermen used Time Lord technology to take over history, they built a Cyber-Ark fleet with which to infect developing planets with Cyber-Technology. In the altered timeline that this meddling created, it was noted that by the 24th century, the Cybermen had evolved beyond the need for the Cyber-Fleet. (COMIC: Supremacy of the Cybermen)