Elemental War

The Elemental War is the destructive conflict between the forces of the Old Gods led by Deathwing the Destroyer and the other citizens of Azeroth (The Horde, the Alliance, and the neutral forces such as the uncorrupted dragonflights). After the second sundering of the planet from his emergence from Deepholm, the cataclysm upheaval was the primary causes of the war between the Horde and the Alliance.

Background
With the destruction of the Demon Soul at the Battle of Grim Batol, Deathwing fled to the Elemental Plane of Deepholm to recover and prepare for his return to Azeroth. During his absence, his son, Nefarian attempted to create a powerful dragonflight, with only partial sucess before his defeat in Blackrock Spire. Sometime later, Sintharia created the powerful Twilight dragonflight. By the time the Alliance and Horde set sail for Northrend, the black dragonflight ended its battle against Ragnaros, allying with the Firelord and Ala'kir the Windlord.

By the end of the war against the Lich King, Deathwing had completely recovered from his defeat. Shortly after the heroes of Northrend returned home, Deathwing prepared for his return, sending earthquakes and shockwaves cross the planet. Allying with Deathwing, the cultists of the Twilight Hammer began spreading word of doom and destruction to the races of Azeroth, leading up to an attack of major cities by various elementals. Though the first attacks were stopped, Deathwing finally emerged from the Maelstrom, destroying the World Pillar in Deepholm and causing the Second Sundering.

The Cataclysm
The Shattering caused by Deathwing's return reshaped the face of much of Azeroth. Entire areas were devastated, resources lost, and raging elementals attacked. The upheaval caused the Horde and Alliance to fight each other for resources, while battling the members of the Twilight Hammer wherever they could.

Hyjal and Vashj'ir
While massive resources was spent on war against the counterpart faction, the Horde and Alliance eventually turn their focus on the forces of the Twilight Hammer and Deathwing, directing forces to Mount Hyjal, where many forces of the Twilight Hammer rest.

The Defense of Hyjal
At some point prior to the Cataclysm, Malfurion Stormrage finally awake from the Emerald Dream, leads the Cenarion Circle against the Twilight Hammer at Mount Hyjal. Ragnaros, after being banished in the Molten Core was resummoned to Azeroth by Deathwing to destroy the World Tree of Nordrassil. Ysera, who herself is awake and active in the campaign against the Twilight Hammer, has adventurers reawaken other Ancient guardians to aid in the battle.

Invading Vashj'ir
Elsewhere, an island appeared off the coast of Stormwind, which is vital to both the Alliance and the Horde in their ongoing conflict. En route to the island however, the ships were attacked and all aboard were pulled into the sea by naga. It is eventually learned that the naga, allied with Deathwing and the Twilight's Hammer, are waging a war against Neptulon the Tidehunter, in an effort to take control of the seas themselves. Rather than allowing the naga to take control of a powerful domain, the mortal races aid the Tidehunter repelling the naga. The Naga are overall victorious however, invading the Abyssal Maw and forcing Neptulon into hiding/imprisonment. While heroes attempted to aid Neptulon as he cleansed the waters, the Krakken Ozumat pulled a weakened Neptulon away as it fled the battle.

Repairing the World Pillar
The Cataclysm brought Azeroth closer to the Elemental Planes than it has ever been. The shaman of the Earthen Ring, feeling the distress of the planet, work to repair the damage Deathwing caused. Thrall, gave the title of Warchief of the Horde to Garrosh Hellscream while he and other shamans like and  tried to stabilize the rift within the Maelstrom, keeping Azeroth from collapsing into Deepholm. Forces of the Horde and Alliance have joined forces with the Earthen Ring to repair the World Pillar, but must battle the Twilight Hammer in Deepholm to recover the misses pieces. Rather than join the Ragnaros and Al'akir, Therazane the Stonemother chose to side with the mortals, to prevent her enemies from taking her realm, or even, its eventual collapase.

Uldum
Please add any available information to this section.

Twilight Highlands
Dominated by the Old God's forces, Grim Batol is under siege by the red dragonflight. and face off above the fortress, mortally wounding Alexstrasza and weakening Deathwing. Elementals run rampant across the land, serving the Twilights hammer cult. Please add any available information to this section.