In 1986, a new Martyrdom Altar was installed in the northwest transept, on the spot where Thomas Becket was slain, the first new altar in the cathedral for 448 years. Mounted on the wall above it, there is a metal sculpture by Truro sculptor Giles Blomfield depicting a cross flanked by two bloodstained swords which, together with the shadows they cast, represent the four knights who killed Becket. A stone plaque also commemorates Pope John Paul II's visit to the United Kingdom in 1982.