- Woman’s body was uncovered during church renovations in Basel in 1975
- There was no gravestone meaning scientists were stumped about who she was
- DNA testing revealed she was wealthy Basel woman Anna Catharina Bischoff
- There were traces of mercury, used as a cure for syphilis, on her remains
- Her son in law was Pfeffel von Kriegelstein, a relative of the UK Foreign Secretary
The woman’s mummified body was uncovered in Basel in 1975 during renovation works to the city’s Barüsser Church.
Mystery has surrounded her identity ever since, with no gravestone to determine who she was.
But over 40 years later, DNA experts have finally revealed the woman is Anna Catharina Bischoff – one of the UK’s Foreign Secretary’s ancestors.
The Foreign Secretary said he was ‘excited’ to hear that the unknown mummy, discovered four decades ago, has now been identified as his ‘late great grand ‘mummy”.
Mr Johnson tweeted: ‘Very excited to hear about my late great grand ‘mummy’ – a pioneer in sexual health care. Very proud.’
As for Anna Catharina herself, she was part of the wealthy Basel family the Bischoffs and married a church minister, the BBC reports.
She lived in Strasbourg, France, for most of her life, where she looked after people with sexually transmitted diseases.
Through her work she contracted syphilis, returning to Basel for intensive mercury treatment – but her efforts to find a cure were in vain.
She died of suspected mercury poisoning in 1787 aged 68.
The key to finding out who she was came in 2017, when Swiss archives were uncovered showing the body had been exhumed once before – in 1843.
Experts suspected she came from a wealthy family as many of the city’s richest residents were buried in churches like Barüsser.
Her coffin, unmarked, was also found in front of the altar, a sign of great respect and importance.
But the papers gave them even greater reason to believe she was one of the Bichoffs.
Scientists managed to extract DNA from the mummy’s big toe and compared it to living relatives of the Bischoffs.
When the results came in, it was a 99.8 per cent match.
Once her identity had been revealed, experts traced her family tree.
Anna Catharina had seven children, but only two survived childhood.
Skipping five generations of Pfeffel von Kreigelstein’s, the historians discovered Marie Luise von Pfeffel married Stanley Fred Williams.
Their daughter married a man called Osman Wilfred Johnson Kemal, whose son is Stanley Johnson – recent star of I’m A Celebrity…Get Me Out Here and father to the Foreign Secretary, 53.
Mr Johnson, 72, is also the father of Mail on Sunday columnist Rachel Johnson, 52, who was recently evicted from the Celebrity Big Brother House.