Dawn War

The Dawn War was an ancient prehistoric conflict between the gods and the primordials over the fate of the world. The gods won a narrow victory, but the consequences of the war still endures after centuries and millennia.

Background
The primordials created the world out of the leftover material that existed between their domain, the Elemental Chaos, and the domain of the gods, the Astral Sea. They discarded material that contained too much positive or negative energy; these pieces coalesced into the Feywild and the Shadowfell, respectively. The world was then one of elemental fury, engulfed in an endless cycle of destruction and rebuilding.

The gods looked down from the Astral Sea and discovered the world that the primordials had created. They became fascinated with this new world and attempted to improve upon the primordials' work. The gods created natural life, tamed the churning elements, and created the Sun and Moon. The primordials did not appreciate the gods marring their work and grew antagonistic of them.

Taking inspiration from the gods, the primordials created their own race, the giants, to serve them in their ultimate goal of destroying the life that the gods had created and returning the world to its chaotic state.

After eons of rising tensions between the gods and primordials, it had become clear that war would be inevitable.

The First Strike
The god Tharizdun sought a secret means to destroy the primordials by himself and discovered a shard of pure evil created by ancient entities. Claiming this shard warped Tharizdun, driving him mad and twisting him into an entity of pure evil. Seeking to destroy the primordials, he planted the shard into the heart of the Elemental Chaos, where it took root and grew into the Infinite Layers of the Abyss, a realm of darkness, despair, gloom, and evil. This act was seen as a first strike by the gods against the primordials, and so began the Dawn War. The gods imprisoned Tharizdun and sealed him away for what he had done.

The War
In retaliation, the primordials invaded the Astral Sea and caused irrevocable damage to the domain. Seeing the chaotic assault of the primordials, the gods organized a coordinated counter-attack strategy and established that each of them would champion and care for specific aspects of creation, which they called "portfolios."

Disorganized, the gods could not gain an upper hand in the Dawn War. Achra, God of War, took command and led the gods to their first big victory against primordials in the war. After several more victories, the primordials came to fear him and call him "Bane" - so Achra adopted this new name with pride.

During the Dawn War, Io chose to fight primordials by himself, confident in his might. However, he was betrayed by fellow god Zehir, and cleaved in twain by a primordial with an adamantine axe. The two halves of Io became two new gods: Bahamut and Tiamat.

Amoth, God of Justice and Mercy, is killed by primordials. Bahamut takes on the domain of Justice. Lakal, Goddess of Healing, takes on the domain of Mercy.

Lakal, Goddess of Healing and Mercy, is killed via collateral damage. Pelor takes on the domain of Healing.

The gods ultimately won the Dawn War. Most primordials were either slain or imprisoned; some remain free, but in exile. Weakened and weary, the gods retreated to their domains in the Astral Sea.