Wesker was born in a cesspool of filth and runoff that could only be called a village in name. Of his parents 5 children he was the only one to survive to adulthood. He apprenticed for a human alchemist as a teenager until an unknown disease spread throughout the village, taking the alchemist and many of the other villager's lives. On his deathbed, Wesker made a promise to his master to learn the practices of medicine in order to help whoever he could reach. After graduating medical school, he now works as a doctor for coin in order to fund his lifelong research project: a Catalogue of Illness and Miasmas.