What you are about to read is pure fan fiction, & only certain aspects remain canon to the original work by Hiromu Arakawa.
Introduction:
This story takes place in the mid 1600s', where Hohenheim Elric grew up as a child. Alchemy is only limited to few people, & those who use it work under the King as guards to society. With their Mother passed away, Hohenheim's Father has gone under depression, & ignores his job as General to the King. Hohenheim desires to learn Alchemy, & shape society right to save it from it's falling state.