Noble
The Nobles were a race of humans on [[Scadrial].
The nobles were effectively created by the Lord Ruler when he forcibly divided the people of the world. The nobles were descendants of the people who supported the Lord Ruler on his rise to power. Due to centuries of (mostly) keeping to themselves, nobles and skaa have basically diverged into two distinct races of humans. All Allomancers had a noble descendant somewhere along their heritage. This is because when the Lord Ruler came to power, he gave his initial supporters beads of lerasium which imparted to them the powers of a Mistborn.
Culture
The life of the nobles was rife with secrecy and plotting. Almost all nobles were driven by gaining money, power, or social prestige.
All nobles were divided among different Houses. Each house had its own agenda and worked towards its own betterment. Each house individually had its own political enemies and allies. Generally, leadership of a house was inherited.
Powers
many (but not all) nobles were Allomancers to some degree. Very few, however, are actual mistborns. This was due to the thinning of Preservation's power through the generations of nobles.