The warrior clans of Mandalore were believed to have been wiped out ages ago, their tattered remnants exiled to the Concordia moon. But as the Clone Wars swept the galaxy, the treacherous governor Pre Vizsla resurrected the Mandalorians, and with them, their legendary combat armor that was feared across the galaxy. Backed by Count Dooku and the Separatists, Vizsla began building an army to retake Mandalore from the control of pacifists who were trying to bury violent Mandalore's past.
As the coup became inopportune, Dooku abandoned the Death Watch, leading once again to their exile. The Death Watch became a murderous band of nomadic outlaws, battle-worn rogues that wandered the Clone Wars.
Dedicated to preserving Mandalore's warrior past, the Death Watch was opposed to Duchess Satine Kryze's push for pacifism.
As the secret leader of Death Watch, Pre Vizsla also used his position as Governor of Concordia to further their cause.
Count Dooku backed the Death Watch movement in hopes of destabilizing Mandalore and gaining a powerful ally in the Clone Wars.
Obi-Wan Kenobi investigated the Mandalore plot -- a mistaken notion that Duchess Satine might be building her own military -- only to discover the return of Death Watch.
Jango Fett had no known association with the Death Watch -- except for wearing the same Mandalorian armor. The officials of Mandalore disavowed any connection to Fett. They claimed Jango was simply a bounty hunter who somehow stole an artifact from the planet's troubled past.