In 1922, a country solicitor from the little town of Hay-on-Wye, nestled on the border between England and Wales, was in prison awaiting execution for murdering his wife. Major Herbert Rowse Armstrong – he always insisted on the rank – had been convicted at a sensational 10-day trial of killing his wife Katharine 15 months earlier. It was said he had dosed her with arsenic that he had bought legally in the local chemist’s shop, allegedly to kill the dandelions on the couple’s lawn.

The case of Major Armstrong was so extraordinary that it seized not only the imagination of newspaper readers in Britain, but across North America and the rest of the English-speaking world. The twists and turns in the tale also inspired a new breed of crime novelists. It was, the Charlotte Observer in far-away North Carolina announced, citing the notorious medieval Italian dynasty: “The greatest poison drama of the century… All England is thrilled by the trial of a modern Borgia.”

The story had everything, as it apparently involved far more than a private domestic tragedy, taking in petty professional rivalries and gossip; rumours that gave rise to astonishing speculation about a man who had been a pillar of the community. There were even tales of a poisoned box of chocolates and a deadly scone handed over at a tea party, allegedly with the words: “’Scuse fingers.”

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Who was Herbert Rowse Armstrong?

Herbert Armstrong was a short, slight, dapper man, only eight stone in weight. He had strikingly blue eyes behind his gold-rimmed pince-nez spectacles and fashionably waxed the ends of
his moustache. He was the picture of respectability, prominent at both the parish church and Freemasons’ lodge, and served as clerk to the justices at three local magistrates’ courts. He had been born into a middle-class family in Plymouth in 1869 and, after his father died, had been educated at Cambridge with financial support from two maiden aunts. He qualified as a solicitor in Liverpool before moving south, first to Devon, and then to take up a partnership at a legal firm in Hay.

Armstrong had married his wife Katharine in 1907. She had been a school mistress and the couple had three young children. “I never knew a happier couple,” wrote their former vicar. Herbert was always attentive to his wife, who – according to local gossip – was nervy, highly strung and bossy, and once interrupted a tennis match in which her husband was playing with the command that he must come along because it was his bath night.

The family lived in a large house in the hamlet of Cusop, just outside Hay, and by 1914 Herbert had taken over the solicitor’s firm. He had served in the Territorial Army for 20 years, so when World War I broke out he quickly volunteered, though he spent the conflict behind a desk, mostly in England.

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Sickness and suspicion

When the war ended, Armstrong returned to Hay and picked up where he had left off, though economic conditions made the job difficult. Katharine, meanwhile, seems to have been badly unbalanced by the war. She developed neuritis in her hands, which prevented her from playing the piano, and started suffering from delusions, convinced she was a bad wife and mother and had been cheating the local tradesmen. Eventually, in the summer of 1920, her husband – with the consent of her sister and the local doctor, Tom Hincks – agreed that she should be committed to the Barnwood Asylum in Gloucester.

Katharine spent six months in the hospital before being released in January 1921, but her condition rapidly deteriorated. On one occasion, she apparently asked the family’s housekeeper whether she would kill herself if she fell out of an upper floor window. Within a few weeks, the former school mistress was desperately sick and unable to move, and a month after coming home, she died. At the time it was believed that it had been a natural death, and Armstrong’s friend Hincks signed the certificate with a diagnosis of “gastritis, heart disease and inflammation of the kidneys”.

Life returned to normal, but Major Armstrong had growing difficulties with a young solicitor named Oswald Martin, who had moved to a rival firm after the war. Martin – who was married to Connie, the daughter of local chemist Fred Davies – was a pushy figure who fell out with Armstrong over the sale of a local estate. Martin represented tenant farmers who wanted to buy their farms, while Armstrong handled the sale for the owner. Property prices had fallen sharply and the tenants wanted to renegotiate, but the owner was in financial difficulties – he owed money to Armstrong that he could not repay without the sale. This left the major in debt, and the sale grew acrimonious.

In October 1921, Armstrong invited Martin to tea at his home, during which he handed him a scone, allegedly saying “’scuse fingers”. After he went home and had his supper, Martin fell excruciatingly sick, though he recovered in a few days. He and his wife then remembered that they had received an anonymous gift of a box of chocolates through the post a few weeks earlier and that after tasting one, his visiting sister-in-law had also fallen sick. It was then that Connie’s chemist father, Fred, recalled selling large quantities of arsenic to Armstrong to use as weedkiller on his dandelions. The sale of poisons was not strictly regulated then, and purchasers only had to sign a register when they bought some.

Fred’s suggestion alarmed his son-in-law, and triggered a change of mind in Dr Hincks, who had treated Martin only for gastroenteritis. He started to wonder whether Katharine Armstrong had been poisoned too, and sent his concerns to the Home Office, which tested a specimen of Martin’s urine. It had a small trace of arsenic in it, but not enough to kill him. Two detectives from Scotland Yard were sent to Hay to carry out an undercover investigation.

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The arrest of Herbert Rowse Armstrong

Over the coming weeks, Oswald became terrified of any contact with the major, particularly when he was repeatedly invited across the road from his office to Armstrong’s for afternoon tea. He thought the major would try and poison him again, though Armstrong’s friends thought it was more likely that the major was just lonely and wanted to discuss masonic affairs.

The arsenic finding – and rumours that others might have been poisoned too – led the Home Office and Director of Public Prosecutions to act, and Armstrong was confronted by police in his office while doing paperwork on New Year’s Eve. During their search, a little packet of arsenic was found: Armstrong had been wearing his gardening clothes and it had been in his pocket. Instead of an afternoon’s gardening, the major was arrested. He did not realise it at the time, but he would never see his home or his children ever again.

Within days, Katharine’s body was exhumed from the local churchyard and a post-mortem was carried out by Bernard Spilsbury, the leading pathologist of the day. When tested, her organs were found to contain a lethal amount of arsenic.

The trial and verdict

Many local people were astonished at what had happened – Armstrong had represented many of them and was well liked, whereas the young newcomer, Martin, was not. Now the major found himself arraigned in his own court, charged with the murder of his wife and the attempted murder of his rival. He protested his innocence.

Armstrong’s trial took place at Hereford Assizes in April 1922 and, although the evidence against him was circumstantial and he had one of the most eminent barristers in the country, Sir Henry Curtis-Bennett, defending him, the major was facing an uphill battle. Remarkably, there had been a previous case only a year earlier when a Welsh solicitor named Harold Greenwood had been acquitted of poisoning his wife after a sloppy police investigation, and the authorities were determined that it should not happen again.

The judge, Mr Justice Charles Darling, continually ruled against the defence (most crucially in allowing evidence of Martin’s illness to be heard) and he cross-examined Armstrong ferociously. In his summing up for the jury, the judge dismissed the arguments put forward by Curtis-Bennett and praised Spilsbury and the other witnesses for the prosecution. It was little wonder that the jury took a mere 48 minutes to convict the diminutive solicitor – and that included a stop for tea.

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What happened to Herbert Rowse Armstrong?

Armstrong’s appeal failed and he was hanged at Gloucester Prison on 31 May 1922, exactly five months after his arrest. The hangman claimed that as he pulled the lever to open the trapdoor beneath the major’s feet, he heard him whisper: “I’m coming, Kate.”

The case, with its irresistible twists and turns, was reported in huge (and sometimes prejudicial) detail by the popular press – tens of thousands of words a day, some of them by the famous author Edgar Wallace – and the overwhelming assumption was that Armstrong was guilty.

But was he really? There were considerable holes in the prosecution case and several questions remained. Could Katharine have poisoned herself in despair? Was Martin only suffering from a tummy ache? Who sent the anonymous chocolates? Why would Armstrong kill the wife to whom he seemed devoted?

The children of Herbert Rowse Armstrong

Tragically, the outcome left three small children orphaned and taken into foster care. It is said that the youngest only found out what had happened to her parents on a school visit to Madame Tussauds, when she came face to face with her beloved father in the Chamber of Horrors.

Art imitating life

The story of Katharine Armstrong’s demise inspired the greatest authors of the age…

George Orwell wrote in a 1946 essay: “What would be… the ‘perfect’ murder? The murderer should be a little man of the professional class living an intensely respectable life… he should plan it all with the utmost cunning and only slip up over some tiny, unforeseeable detail. The means chosen should of course be poison.”

He made it clear he was thinking of Major Armstrong, and indeed the case coincided with the rise of crime novelists such as Agatha Christie and Dorothy Sayers, both of whom incorporated elements of the story in some of their plots.

Their stories, like those of several other contemporary bestselling writers, involved amateur sleuths solving cunning and complex murders among the middle classes through ingenuity, almost like a game. The books were very popular in the 1920s – a thousand new titles a year were being published by the end of the decade – and the real- life Armstrong case fit the genre perfectly: a true crime just as vivid as fiction.

Stephen Bates is a former senior correspondent for The Guardian. His new book about Major Herbert Rowse Armstrong, The Poisonous Solicitor, has just been published by Icon Books

This article first appeared in the May 2022 issue of BBC History Revealed