Kalen was the first born child of Arro Dayne, reigning head of house Dayne, and one of the greater of the lords sworn to Prince Mors Martell in the unification of Dorne. That he was not born of his wife might have been a great concern in one of the kingdoms north of the Red Mountains, but within the region of Dorne bastards were acknowledged as often as daughters, and Kalen came to be taken into Arro’s household to be raised as his heir when his wife seemed incapable of producing him a trueborn child. Kalen grew to become a talented natural warrior, dexterous and agile, and became quite proficient with the spear as well as the care and riding of horses.
When Kalen was fifteen, Elora Dayne finally produced a child for her lord husband, and although it was not uncommon for the eldest child to retain a claim to the high seat of a house despite being a bastard, nor was it uncommon for an illegitimate heir to be set aside in favor of a younger trueborn sibling. So it was with Kalen once his half-brother Davrick Dayne began to mature and it became clear that he was neither a half-wit nor a sadist.