The Keyblade War refers to a significant conflict in the lore of the Kingdom Hearts series. It was fought between various factions over the control of the Keyblade, a powerful weapon that can unlock and protect worlds. The war resulted in widespread destruction and the loss of many lives, leading to the creation of the Keyblade Graveyard, a desolate area filled with the remnants of fallen Keyblades. This conflict was primarily driven by the desire to obtain the X-blade, a legendary weapon said to hold immense power. The war involved key figures such as Master Xehanort and various other Keyblade wielders, each with their own motives and allegiances. The aftermath of the war shaped the future of the worlds within the Kingdom Hearts universe.