A syphilis-ridden mummy in Switzerland is a distant ancestor of Boris Johnson

Reuters/SRF

Boris Johnson and the skull of Anna Catharina Bischoff, an 18th-century noblewoman from the Swiss town of Basel.

• A well-preserved mummy in Basel, Switzerland, has long been a mystery.
• New analysis has found her identity: Anna Catharina Bischoff, an 18th-century clergyman's wife, and distant ancestor of UK Foreign Secretary Boris Johnson.
• She's his great-great-great-great-great-great-great grandmother.
• Her body is so well-preserved because of mercury used to treat her syphilis.

A mummy whose corpse was ravaged by syphilis and buried in a Swiss mountain village has been identified by scientists as a distant ancestor of British Foreign Secretary Boris Johnson.

The preserved body, which was unearthed decades ago in Basel, Switzerland, has been given a definitive identity for the first time after extensive research. And the results place her on the same family tree as Johnson.

SRF

A full-length view of the mummy, which owes its preservation to large doses of mercury, probably administered as a primitive treatment for syphilis.

According to SRF, a Swiss TV channel which has produced a documentary on the mummy, she is Anna Catharina Bischoff, an 18th-century clergyman's wife. She was discovered under Basel's Barfüsser Church in the 1970s during renovations.

According to the BBC, Bischoff's identity has been established by scientists with 99.8% certainty. She is Johnson's great-great-great-great-great-great-great grandmother, meaning she is nine generations away from him.

SRF, citing Swiss archives, said that Bischoff lived from 1719 to 1787, and died aged 68 from syphilis.

Bischoff is referred to as a mummy, but she had an ordinary Christian burial, and her body wasn't kept intact on purpose.

SRF

An artist's impression of what Anna Catharina Bischoff may have looked like.

Rather, according to the BBC, her body was preserved by accident thanks to the large quantities of mercury she ingested.

At the time she was alive, doctors believed mercury could help treat syphilis, but it was much more likely to have hastened her death.

Business Insider has asked a spokesman for Johnson to comment on the discovery, but has yet to receive a response.

More details on the mummy will be broadcast on Thursday evening in an episode of the SRF documentary series "Einstein."