Joseph Blackwell was an extremely powerful Witch, with Dark Magic. the son of E. Blackwell, and Jane Thomas, the grandson of Francis Balcoin, the father of James Blackwell, the grandfather of Samuel Blackwell, the great-grandfather of John Blackwell, and the ancestor of Cassie Blake, Diana Meade, and John Blackwell's four other unknown children. He has yet to physically appear on the show, but was listed on the Blackwell family tree. He was born in 1839 and died in 1920.
Joseph was a member of the Blackwell Family.