"The Horadrim are all gone, so you become a storyteller to fill the emptiness. But the people of Tristram are laughing at you. Look around you, Mother! Where are your angels, your demons? Where are your heroes? The Horadrim are long dead and the town's no different for it!"— Deckard Cain to Aderes(src)
Aderes Cain was one of the last members of the Horadrim. Her skin had a waxy sheen, and her hair was black and curly, though started to go gray late in her life.
Aderes lived in Tristram. She married a tanner and had a son with him named Deckard. Despite Deckard's wishes to the contrary, she insisted that he take the name of Cain, rather than his father's surname. In her later years, she would tell the children of the village tales of the deeds of the Horadrim, in their quest to imprison the Prime Evils. She would tell the same stories more than once, and they became more extravagant each time.
In 1213, events came to a head as sickness took her husband. By this stage, Deckard had lost interest in his mother's stories, believing them to have no basis in reality despite her insistence to the contrary. It was only made worse when Deckard discovered that his mother had burnt his history books, Aderes insisting that his "proper reading" was with the texts written by his ancestor. It was the straw that broke Deckard's back, and Aderes's too, as she declared her son lost.