Married at 19 when she was already pregnant, Sarah Chesham gave birth to five more children by the time she was 30. Then something must have gone disastrously wrong in her mind – or with her marriage.

For in 1847 two of her sons, James and Joseph, died in agony, vomiting copiously. Post-mortems revealed traces of arsenic in both bodies, and Sarah was charged with their murder.

A Clavering farmer, Thomas Newport, was arrested for aiding and abetting her, and it was rumoured that they were having an affair. But although it was clear that the boys were poisoned, the evidence was thin and Sarah was acquitted.

Three years later, in May 1850, Sarah’s farm labourer husband Richard, 43, died after a long illness, and was buried at Clavering church. He had suffered from a lung disease, with intermittent bouts of violent pain and sickness, and some of the neighbours suggested that Sarah had been poisoning again. There were in fact tiny traces of arsenic in Richard Chesham’s body, but not enough to suggest that his wife had helped him on his way.

Sarah had a friend, Hannah Phillips, who continually complained about her husband. “Phew!’ Sarah once told her. “I wouldn’t live with such a man.” And then she gave Hannah some advice on how to get rid of him.

The two friends were much maligned by the villagers, who dubbed them both “Sally Arsenic.” There was nothing to prove against them, however – or at least there wasn’t until they fell out. Then Hannah went to the police and told them what Sarah had been telling her.

“She told me to bake a pie of liver and lights, and she would provide a special seasoning of poison, which would dispose of my husband,” Hannah said.

Richard Chesham’s body was exhumed; police raided Sarah’s house and removed a bag of rice which was mixed with arsenic, and Sarah was charged with the attempted murder of Hannah’s husband, rather than the murder of her own. She was hanged on Tuesday, March 25th, 1851, outside Chelmsford Prison before a crowd of 7,000, the last woman to be executed in Britain for attempted murder.