Joseph Sundvik lived in the Yorkshire seaside village Maiden's Point where, centuries earlier, Vikings had buried the flask in which the Doctor had imprisoned Fenric.
He was born on 8 April 1809 and died on 3 February 1872. He was buried in the local churchyard. The Seventh Doctor and Ace read his tombstone in 1943.
From the Doctor's research into the parish records, it was determined that Sundvik may be an ancestor of the contemporary Dudman, Millington Wainwright and Judson families living in the village at the time through his various daughters. Fenric confirmed he was the great-great-grandfather of Captain Sorin through his granddaughter, Emily Wilson. (TV: The Curse of Fenric)