The Sandstorm War
All knowledge from before the Sandstorm War--called also the Dawn War, the Firstblood, and the Crown-Crafter's War--is widely believed to be lost to history. Even the nature of the conflict itself is uncertain, save that it was a terrible conflict where the Shining Races and their allies matched forces with the First Giants, the legendary Titans.
From it were born the Lesser Giants known today as well as creatures such as the ogres, trolls, and fomorians.
Hearsay about the war holds that the Titans were possessed by blasphemous spirits that made them preach lies about Great Azuri. When other races refused to be converted to their new beliefs, the Titans emerged from their strongholds--many of which were located in a vast desert, hence the war's name--and brought war to every corner of the world. Victory was only possible by calling down a great and terrible curse that withered the Titans, depleting their vitality and leaving husks of them behind: what men call giants today.