Josef Kostan né Josef Konstantin. Josef changed his last name to Kostan when he moved to Los Angeles.
His previous name and possibly his true name was and is Josef Konstantin. Not much is known about Josef's turning or his human life or human family. He has mentioned that when he was human he never had children or at least none he was aware of. He is well over 412 years old and one of the oldest vampires known to Mick.
He had a hundred year on off relationship with a vampire called Lola who he believed was older than he was.
He previously went by the name Charles Fitzgerald in New York City during the nineteen-fifties. In 1955, Josef met and fell in love with a woman called Sarah Whitely. She begged him to change her and when he gave in, Sarah fell into a coma. Staying young yet never waking up Sarah is kept in a private house in New York. Afterwards Josef vowed never to try to turn anyone again and often counsels his best friend, Mick St John, about the dangers of human-vampire romantic relations.
Currently lives in L.A. and goes by the name "Josef Kostan". To the public he's a hedge fund trader. To vampires he's one of the city's oldest and most powerful citizens. He sits on the board of numerous charities and has a substantial global financial empire. He may or may not be dating his favorite Freshie and Lawyer, Simone. His closest friend is Mick St John, his "only friend who doesn't like him just for his money". He became Mick St John's Step-Sire when he re-turned Mick after he'd taken Coraline Duvall's "cure" for vampirism.
He really is shown to not care for anyone but himself but occasionally shows feelings for others with his expressions, and occasionally tearing up if watched closely. Even though he is quite witty, he is very smart and has seen so much history he is history himself. He has learned so much in his 412 years that he sometimes quotes clever little stories with hidden meaning behind them.