Eons ago, the virtually omnipotent Nemesis tired of life and scattered her essence into several gems, each bearing power over one aspect of existence. The Infinity Gems were coveted by some, feared by all. Having previously tapped their power in a plot to obliterate the stars, Thanos of Titan eventually accessed the full power of six gems, forming the Infinity Gauntlet to gain practical omnipotence. Adam Warlock wrested the Gauntlet from Thanos, using it to expel his own good and evil aspects, but the Living Tribunal and other cosmic beings found him unworthy of the power. Warlock retained the Soul Gem and dispersed the others to chosen protectors: the Time Gem to his sometime lover, Gamora; the Space Gem to Pip the Troll; the Power Gem to Drax the Destroyer; the Mind Gem to Moondragon; and the Reality Gem to Thanos, inexplicably chosen during Warlock's seeming omniscience, his involvement remaining secret.
Initially a loose-knit group, each Watch member operated independently until Warlock's old foe the Man-Beast, calling himself Omega, captured four members, draining their Gems' power and creating the monstrous Infinity Thrall. Warlock defeated the creature, and the Watch, sans Thanos, realized they needed more structure and moved into a castle on Monster Island, offering protection to its owner, the Mole Man. Shortly after this, the Magus - the reborn evil part of Warlock - embarked on "the Infinity War," using evil doppelgangers of Earth's heroes and plunging the universal manifestations Eternity and Infinity into catatonia. The world-devourer Galactus used Gamora to revive the cosmic beings, and Adam absorbed the Magus into his Soul Gem, but was left comatose. Meanwhile, the U.S. Army invaded Monster Island under the manipulation of Senator Kyle Munson. The all-seeing Eternity revived Warlock to stabilize the Watch and continue his own unique destiny. Warlock also gained the Orb of Eternity, to observe distant events.
Shortly thereafter, the evil Lord Abyss sought the Soul Gem to repair his own soulless state. His threat was superseded by the Goddess, the "good" part of Warlock, who sought to extinguish all life to rid the universe of sin. Empowered by numerous Cosmic Cubes, she manipulated certain heroes, including Gamora and Moondragon, into fighting their former friends. Joined by the amnesiac hero Maxam, despite Gamora's objections, the Watch thwarted the Goddess' "Infinity Crusade" and trapped her in the Soul Gem, battled an insane Thor, and exposed Munson as the Man-Beast. Via a powerful love potion, Warlock suddenly became infatuated with Maya, the servant of Abyss. Nonetheless, Abyss was defeated, and Warlock allowed Maya to marry the mage Darklore, bringing peace to her home dimension, Egolix-7.
After battles against Tyrannus, and Zakaius and Domitian, the Watch was assaulted by Maxam, who suddenly recalled his mission to slay Warlock (as the Magus had exterminated his family in his alternate future), but they all lost their Gems to the Ultraverse's Rune. Warlock followed the energy vampire back to his home dimension, but was unable to prevent the Gems from being reunited with the 7th Gem, the previously unknown Ego Gem. This allowed the return of Nemesis, who wreaked havoc in both dimensions until being destroyed by the Black Knight (Dane Whitman). Scattered throughout reality, the six primary gems have been briefly regathered by Galactus and the Grandmaster. Warlock retains the Soul Gem, the Champion of the Universe and Titania have since held the Power Gem, and Pip maintains the Space Gem-granted ability to teleport.