You grew up in the Principality of Sablestone in the small Village of Kern before it became the center of adventuring for the region. You were raised by your mother and her family but never knew your father. He left one day when you and your sister were young never to return. The things you do remember of him are more like flashes of emotions rather than true memories but you are certain he loved all of you and wouldn't have abandoned you all. That sentiment was reinforced by your mother; she spent a great deal of time telling you all about the man your father was and you grew to revere his memory.
The stories your mother told you and your sisters about the honor and moral decency of your father guided your life. You wanted nothing more than to be just in both her eyes and his if you ever had the grace of the Immortals to cross his path. That strong sense of charity and righteousness led you to seek the patronage of an Immortal to serve their holy champion. A cleric of Mitra passed through the Village of Kern and found in you an eager apostle. Everything about Mitra spoke to you and after sometime she literally did. Through otusider agents you were invested as a Paladin of Mitra, a templar of justice. You took to your duties with zeal, protecting the miners that came to plumb the depths of the Kurish Massif mountains.
You stumbled only once in service to Mitra. It was shortly before the Great War when your mother was killed in a freak accident; a runaway wagon struck her, killing her. The grief of that loss caused you to feel abandoned by Mitra; a feeling that left a hole in you. You filled that hole as most men do, by seeking solace in the arms of another. This solace took the form of an adventurer having recently arrived to Sablestone to find wealth and fame in the mountain region. This dalliance caused you to break a vow to Mitra; something that caused you to briefly lose her favor. Wracked with guilt you sought out the Cleric of Mitra that taught you the ways of Mitra and sought absolution for your trespass.
You were given the blessing of Mitra for your transgression and picked up the mantle of her servant once more. You vowed to yourself to not waver ever again. As if to test your vow, by the grace of Mitra, a swaddled babe arrived at your doorstep. That adventurer left your son on your doorstep and a note pleading with you to raise him as she could not. The paternity of the babe was not in question, it was swaddled in the tabard you had left behind and though the mother was not an Aasimar the babe clearly was. You took the babe in and prayed to Mitra for guidance. You felt a peace fall over you and knew your patron gave her blessing to you.
You knew you were not equal to the task of raising your son so you sought the aid of your sister, who took in the child without hesitation. You then set off in search of the child's mother, eager to help her to return to her son. You came close to finding her several times but there always seemed something that prevented you from reaching her. It was never a tangible thing that kept you from reaching your goal but more like a twist of fate that would put people requiring your aid. So time and again you found yourself keeping your vow to serve Mitra, while the goal of finding the mother of your child was just out of your reach. This pattern repeated itself many times and over the course of your travels you found several companions to share in your wandering. These companions have proved to be fast friends, if not always in line with your code, they at least respect it enough to not undermine it.
When your companions decided to travel to Glantri City to attempt to gain entry into the Great School of Magic you saw it as an opportunity to help a great many people and possibly find a clue as to the whereabouts of your former paramour.