Hohenheim (referred to as Hohenheim of Light in the anime or Van Hohenheim in the manga) is a fictional character in the anime and manga series Fullmetal Alchemist, is the father of the protagonists, Edward and Alphonse Elric. He is a brilliant and well-known alchemist. He left Ed, Al, and their mother Trisha when Al was a baby and Ed was very young. Years later, Ed still holds a grudge against him for abandoning his mother, which he believes contributed to her death.

Source: Wikipedia