Doctor Who: 10 Things You Didn't Know About The Twelfth Doctor
6. He's Wearing Peter Capaldi's Wedding Ring
Throughout his era, the Twelfth Doctor wears a band on his ring finger. There's no story reason given for this item of jewellery, though Paul Cornell's novelisation of Twice Upon A Time stated that it's his wedding ring from his marriage to River Song.
However, the real reason that the Twelfth Doctor wears a ring is because it's Peter Capaldi's actual wedding ring from his marriage to actor and producer Elaine Collins – albeit with a sci-fi upgrade.
Capaldi didn't want to take off his wedding ring for the role, and so asked if he could incorporate it into the Twelfth Doctor's costume. The idea was that a second ring would be made, with a disc joining Capaldi's wedding ring with the new piece of jewellery.
This second ring (the one with the green stone) was made by Rowley's jewellers in Penarth. Touchingly, the son of one of the jewellery makers conceived of the origins for the Doctor's ring, explaining that:
"This timeless gold ring contains green amber collected by the Doctor on the planet Raxacoricofallapatorius. It reminds him of all the wars he has won but also all the lives he has taken. This thought lurks on his conscience to this day."
The Twelfth Doctor versus the Slitheen? Now there's an episode we would've liked to see!