The war began with a cosmic being known as the First Firmament, who created the Celestial servants out of loneliness. There were two "factions": the Aspirants who sought its approval, and the Celestials who made creation and wanted their creations to evolve. The First Firmament saw this as sacrilege, and began the war against the Celestials, commanding the Aspirants to wipe them out.
The war began, and the Aspirants and the Celestial rebels fought in a heated combat across the infinite expansion of the known universe and beyond. Both side killed each other evenly, their strength equal as the war raged on. The Aspirants, finding this pointless as they were evenly matched, created the Godkiller Armor, which was proven to be a powerful instrument of destruction, which forced the Celestials to fall back. However, an internal conflict arose for the Aspirants, so they stripped the Godkiller Armour for parts when a civil war began. This allowed the Celestials to recover and destroy their Aspirant counterparts.
Due to the actions of the Aspirants, the stripping of the Armor, and its internal conflict, the Celestials were able to defeat them, and shatter the First Firmament, whose fragments formed the Infinity Stones. The parts of the First Firmament which remained unshattered fled outside of the universe, along with the surviving Aspirants.
When the First Firmament was shattered, and its fragments formed the Infinity Stones, its departure from the universe allowed for the Celestials to release the Abstract Entities from the Chains of Heaven. This event allowed the Celestials to perform their duty as cosmic judges and experiment on life in their liking, performing instances of evolution. The Abstract Entities would also be allowed to stabilize the universe and perform their specific functions in maintenance of the universe.