Age of Giants

With the end of the Age of Demons, other groups were able to rise to power. The first of these groups was said to be the giants. Clever and beguiling, the giants beseeched the dragons to teach them the mysteries of the universe and they did. The dragons granted the giants knowledge of all manner of arcane power. For a time the giants were the dominant force on Eberron, teaching other races what they had learned in small bursts.
However the giants became over-confidant. Through the use of their magic, they nearly destroyed the world over. Enraged at this, the dragons lashed out against their pupils, destroying almost every giant in a earth shattering frenzy. Many citizens of Khorvaire have scarecely heard of giants past that of lumbering brutes and gargantuan tyrants.