The Cyber Legions were fleets of spaceships commanded by the Cybermen. By the 52nd century, there were at least twelve Cyber Legions.
The Ninth Cyber Legion invaded London in 2012 and were destroyed by the Eleventh Doctor and River Song. (GAME: The Eternity Clock)
The Twelfth Cyber Legion was destroyed by the Eleventh Doctor, to make a point to the captors of his companion Amy Pond and her baby daughter, Melody, before he invaded the asteroid station Demons Run. (TV: A Good Man Goes to War)
Fragments of these fleets were encountered by the Eleventh Doctor during his travels. One crashed ship was found in the Arctic at a GSO excavation site in 2010, (GAME: Blood of the Cybermen) another under a shopping centre in Colchester in 2011, (TV: Closing Time) and a third in the village of Klimtenburg during the 19th century, (PROSE: Plague of the Cybermen) all three of which had crashed centuries prior to their discovery.
The suits of a Cyberman from the Cyber Legions, as well as two Cybermen from a parallel universe, were recovered after the Cyber-Wars and became part of Webley's collection at Hedgewick's World of Wonders. (TV: Nightmare in Silver)