The Crossbone Vanguard had two incarnations. The first was in Gundam F91, where they were a private militia run by a group of aristocrats. They got their asses kicked by the Feddies.
Ten years later, the Crossbone Vanguard is revived as a group of space pirates that's assaulting the Jupiter Energy Fleet. This time around, the Crossbone Vanguard is actually an undercover resistance group. The Jupiter Energy Fleet is planning on taking over the Earth, and the Crossbone Vanguard tries to stop it. This version of the Crossbone Vanguard is entirely pirate-themed, and even the Gundams they use have pirate-type elements:
