The Great War: A Tale of Magic & Technology
During the Great War against the Dark Queen, the united races of the Chosen One's Army knew a time of great magic and technology. The united races were the mystic elves, the stout dwarves and the versatile humans. They all fought the Dark Queen, contributing all they could in their epic struggle for freedom.

The elves, born practitioners of magic, created powerful weapons in the shape of magical constructs, magically engineered and enhanced warriors and arcane weaponry. Their mastery of magic was near perfect and so were their weapons.
Their spells, soldiers and golems would have won the Great War if it weren't for the unparalleled magic of the Dark Queen herself. Not only was her mastery of magic perfect, she also perverted it in ways that the noble elves could not think of. For every shining, silver and gold golem that the elves created, the Dark Queen created two golems of gore blood and bones. For every magically bio-engineered warrior, the Dark Queen added a brutal bloodthirsty soldier to her immense Black Legion. And every soldier that died became a horrifying undead warrior in her Legion of Doom.

The dwarves, deep in their mountain halls, didn't really practice magic, but they were unrivaled masters of metallurgy and mechanics. The dwarves created thousands of arms and armors for the united races' army. And it didn't stop at that. They created war machines so powerful that they intimidated friend and foe alike.
Siege engines, mechanical constructs, and the power of steam. These were their weapons against the Dark Queen. But the dwarves were careful with their knowledge. The control over magic cannot be stolen from its wielder but the power of steel and steam can be taken away from you. To prevent this, all their inventinos had a self-destruct mechanism or needed a vital key to operate.

The humans weren't masters of magic or metal, but they were quick learners. A few humans dabbled in magic. The elves warned them that they shouldn't desire too much power because that would lead them to the dark and forbidden side of magic.
A handful learned some of the secrets of metallurgy and mechanics. They were warned to think more about its cost and consequences and less about its power and possibilities.
Most humans became soldiers in the Chosen One's army to fight for freedom or die trying.

During the Final Battle, the Goddess cut her world off from arcane magic. This was known as the Great Rupture. The Goddess paid a terrible price for the Dark Queen's demise: Suddenly all things magical that lived on the Goddess's world had their essence ripped from their very lives. Only the strongest survived and even they were left crippled. The Dark Queen's magic ceased and was ripped from her essence, but so did the magic of the elves. Even though they didn't need magic to survive they were connected to it and felt its disappearance and the pain it caused in the world.

The surviving elves felt betrayed and fled underground, shunning everyone and everything that they felt, had betrayed them. They became the secluded and isolated elves as we know them today.

The surviving dwarves destroyed their war machines and went back underground to try and rebuild all the things they had lost.

The humans, who had all but perished, licked their wounds and bolstered themselves to face a new threat. They now had to survive the desolate, emaciated world instead of a war.

300 years have passed and little remains of all the knowledge of the war. It made rebuilding this world a lot more difficult.

In addition to this you should also read the Lost History of AranoX.