» Mon Feb 04, 2013 6:07 am
Here is the little history there is on Miraak. The first link is not the best of sources, while the second is pretty good.
Miraak History
During the period of time when http://elderscrolls.wikia.com/wiki/Dragon ruled over mortals, Miraak served as a dragon priest on the island of Solstheim. At some point before his death, he came into possession of a black book which in term lead to him in service of http://elderscrolls.wikia.com/wiki/Hermaeus_Mora, the Daedric Lord of Knowledge and Fate, who taught him a http://elderscrolls.wikia.com/wiki/Bend_Will. With this forbidden knowledge in his possession, Miraak turned on his dragon masters, using his power to devour their souls to become ever more powerful. According to http://elderscrolls.wikia.com/wiki/Frea, because of his betrayal, the dragons sought him out at his http://elderscrolls.wikia.com/wiki/Temple_of_Miraak on Solstheim and killed him for his treachery. After his death, he lived on in http://elderscrolls.wikia.com/wiki/Apocrypha, the realm of Hermaeus Mora, until the time was right for his return.
Taken from http://elderscrolls.wikia.com/wiki/Miraak
Miraak is the primary antagonist of the http://www.uesp.net/wiki/Dragonborn:Dragonborn expansion for http://www.uesp.net/wiki/Skyrim:Skyrim, and rival to the player as the first http://www.uesp.net/wiki/Skyrim:Dovahkiin.
He was a dragon priest originally, back when the http://www.uesp.net/wiki/Skyrim:Dragon ruled http://www.uesp.net/wiki/Lore:Tamriel, but turned on them and went his own way. He later sought the teachings of http://www.uesp.net/wiki/Dragonborn:Hermaeus_Mora, and became his champion. However, he eventually decided that the power he was granted by Hermaeus Mora was not enough, and he seeks to be free of him just as he sought to be free of the dragons. He is currently stuck in http://www.uesp.net/wiki/Dragonborn:Apocrypha and can only return once he has gained sufficient power to free himself from Hermaeus Mora's service.
He is never seen physically outside of Apocrypha, except on the occasion that you kill a dragon during the main questline after your first encounter with him. This will continue to happen until he is killed, except for a particular few dragons which are necessary to progress. When Miraak steals a dragon soul from you, he appears to be semi-transparent, although you cannot interact with him at these points.
Taken from http://www.uesp.net/wiki/Dragonborn:Miraak_(NPC)
According to the second link Miraak was a Nord.