In 1975 a mysterious mummified body was uncovered in the Barfuesser Church in Basel Switzerland. Basel in the 16th and 17th centuries was a wealthy trading city and its port on the Rhine was a key hub for moving goods across Europe. The mummy appeared to be a well fed and wealthy woman wearing good quality clothes buried right in front of the altar. There was no gravestone to be found but carbon dating showed the coffin originated from the 16th century. Furthermore the body was in an amazing state of preservation due to being filled with mercury, a highly toxic substance.

In 2017 records showed the mummy had been uncovered once before in 1843. These records also confirmed the body was indeed that of a wealthy and important individual and likely a member of the well-established Basel family, the Bischoffs. The location of the mummy is shown here which was in the family tomb of Isaak Bischoff, a hospital director in 17th century Basel. DNA was extracted from her toe and intially the female haplogroup was compared with modern Bischoff descendants - a perfect match. Now both historians and geneticists could agree on her identity - that of Anna Catharina Bischoff.

It turns out that former British Prime Minister Boris Johnson is a direct descendant of Anna Catharina. She was 67 when she had died and had seven children, one of which married Baron Pfeffel of Kriegelstein - a known member of Johnsons family tree - this makes him a six-times grandson of the Basel mummy. The father of the former Prime Minister has been interviewed on the matter and is very excited to be related to that mysterious Lady of Basel.

But why was there so much mercury in her blood? The mercury had indeed preserved her body very well and is a key reason her remains are so well kept. Anna Bischoff is believed to have died of mercury poisoning which was a common treatment for syphilis in her time. She may have contracted the disease while working as a nurse to syphilis patients. Shown here is the how the treatment would be perormed using mercury vapor - the patient would stand in a small chamber and mercury vapor would be inhaled. Similiar treatment remained commonplace for numerous ailments until the invention of penicillin.