He 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)
In the Fullmetal Alchemist manga he is refered to as "Van Hohenheim," not Hohenheim Elric. As Edward Elric points out in book 14 of the Fullmetal Alchemist manga, "Elric is my mother's name!"
He (in the original 2003 anime)...
He (in the manga and 2009 series) is...