London: Scientists in the Swiss city of Basel have identified a mysterious mummified body after more than 40 years and discovered that the woman is the great-great-great-great-great-great-great grandmother of UK foreign secretary Boris Johnson. The mummy has been identified as Anna Catharina Bischoff, who died in 1787. Her body was uncovered in 1975, when Basel’s Barfüsser church was being renovated. She had been buried right in front of the altar, was well fed, wearing good quality clothes and her body was riddled with mercury — a standard treatment for syphilis from the late 15th to the 19th century. There was, however, no gravestone to indicate her identity.

The mummy (left) has been identified as Anna Catharina Bischoff, who died in 1787

A breakthrough came last year when newly discovered archives revealed the body had been previously uncovered in 1843. Historians then concluded, through thousands of hours in the Basel State Archives, that the mummy was a member of a well-established local family, the Bischoffs. Using the latest methods, scientists were able to extract DNA material from the mummy’s big toe and compare it with DNA taken from living descendants of the Bischoff family. The results were clear, showing a 99.8 per cent probability that the descendants and the mummy were all from the same maternal line.

Anna Catharina Bischoff had seven children. Only two survived childhood, but one daughter, also Anna, married a certain Christian Hubert Baron Pfeffel von Kriegelstein, an ancestor of Britain’s foreign minister, Alexander Boris de Pfeffel Johnson.