Lord James Marchwood was the owner of Ashen Hill Manor in the south of England and the third Earl of Marchwood. In 1665, he employed Erasmus Darkening because Erasmus said that he could make gold. After his children went missing, Marchwood went looking for them. He found Darkening and asked him about them, but then stabbed Erasmus and his transdimensional accelerator with his sword. He later vanished like his children.
In the early 21st century, his "ghost" manifested to defend Sarah Jane Smith from a red-eyed creature. He then vanished.
Following Darkening's defeat he was reunited with his children in the next life. Their actual ghosts were seen by Sarah Jane as she left the manor. (TV: The Eternity Trap)