[1][2] During the Coroner's inquest, the lurid details of Florence's past affair with Dr James Manby Gully, a married man thirty-seven years her senior, became a topic of intense fascination, covered by newspapers ranging from The Times and The Daily Telegraph to The Illustrated Police News,[1][3] as well as publications overseas.

She was the eldest daughter of land speculator, merchant and future politician Robert "Tertius" Campbell and his wife Ann (née Orr).

[4] They were at odds over Ricardo's military career with the Grenadier Guards; she wanted to have a large family, and feared that he would be sent to war and killed in conflict.

[9][4]: 12  The couple moved to Gatcombe Park in Gloucestershire, where they took part in aristocratic pursuits such as hunting, fishing and horseriding, and regularly hosted parties.

[4]: 14  In late 1869 she wrote to her mother that she wanted a separation from Ricardo,[8] but her father regarded the failure of their marriage as "morally offensive";[4] both parents were determined to avoid the scandal that would result.

[4]: 17–18  Several weeks later, on 20 April 1871, Florence received a telegram from London saying that Ricardo had been found dead in Cologne, Germany,[4]: 22  in lodgings he shared with a "female companion.

[8] Author James Ruddick states, however, that the relationship was exposed in May 1872 when Florence was invited to stay at the family home of her solicitor, Henry Brookes, in Surrey.

[4]: 27  Mr and Mrs Brookes returned home from a walk to pick up an umbrella, when they discovered Florence and Gully having sex in their drawing room.

[4] The social consequences were devastating to Florence: two servants threatened to quit, some grocers refused to serve her staff and the invitations she sent out for afternoon tea and dinner were returned without explanation.

"[4] According to author James Ruddick:Neighbours in Balham would later recall the sight of Florence and Mrs Cox travelling together in their open-top carriage, and comment on the attraction of opposites: Florence, the beautiful young widow, with her jewellery and flowing hair; Mrs Cox, the small, shy woman, draped in black, with the hardness and the sheen of a strange insect.

[11][9][10] Prior to the wedding she had decided to retain control over her fortune rather than have it transfer to her new husband, a legal option that had become available after Parliament had passed the Married Women's Property Act of 1870.

[10]: 69  Florence ultimately agreed to a compromise: she would allow Charles to take over the lease to the Priory, as well as all furnishings, and put him in her will, while she retained control of her money.

[10]: 78  Florence had a butler, a footman, a "lady's maid", two housemaids, a cook, a kitchenmaid, three gardeners, a coachman, a groom and a stable boy, in addition to Cox.

[10]: 53  In December 1875 and January 1876, Charles received three anonymous letters, all in the same handwriting, accusing him of marrying Florence for her money and referring to her as Gully's mistress.

[4] Florence left the Priory to stay at Buscot Park, complaining to her parents about Charles' "violent ebullitions of temper" and saying that his "meanness disgusted her.

[4]: 58–59  After her doctor recommended "a change of air", Florence planned a holiday in Worthing, but Charles and his mother opposed the trip due to the expense.

[10]: 118–120  Before going to bed, Charles went into Florence's bedroom to scold her in French for drinking too much that day, as she had since the miscarriage; she had had champagne at lunch, a bottle of sherry at dinner and had asked for two glasses of wine upstairs.

Florence suggested that Charles had had a heart attack after the horse ride, and also mentioned that he was "prone to fainting fits" and that he had been "worried about stocks and shares.

[4] Florence suggested sending for Royes Bell, Charles' cousin and best friend, who was an assistant surgeon at King's College Hospital in London, with his own practice on Harley Street.

[10]: 150, 155  Impressed by the credentials of the many doctors and surgeons who had examined him, the Coroner for East Surrey, William Carter, stated that the cause of death was likely suicide and sought to "spare the feelings of the family" by keeping the inquiry private, perfunctory and not calling Florence as a witness.

"[10]: 158  Troubled with how the inquest was handled, Barrister Carlyle Willoughby, a friend and colleague of Charles, contacted Scotland Yard to voice his concerns.

[10]: 171 On 11 May 1876, The Daily Telegraph first brought national attention to the mystery surrounding Charles' death, denouncing the inquest as having been conducted in a "secret and unsatisfactory manner.

"[17][10]: 168  The sensational article named some of the doctors, gave details about the dinner menu on the night of Charles' death and speculated that the Burgundy wine which he alone had drunk had been poisoned.

[10]: 168–169  On the advice of the Buscot Park physician and her father, for one week, Florence had her solicitor advertise a reward of £500 for anyone who could produce evidence of selling antimony to a member of the Priory household staff.

"[10]: 169  Police found that a large quantity of tartar emetic had been sold by a chemist in Streatham to Griffiths in the summer of 1875, which he used on horses to eliminate worms and stored in the Priory's stables.

[10]: 171–172  Florence suffered a collapse and "brain fever", while Cox abruptly left for the Priory to collect her belongings and move to other accommodations in London.

[10]: 174 On 27 May 1876, the Telegraph reported that the Treasury Solicitor, Augustus Keppel Stephenson, had concluded a preliminary inquiry of thirty witnesses, but that this did not include Florence and Cox, implying that they were both suspects.

[10][4]: 88  Gull believed that Charles had swallowed antimony intentionally but lost his nerve and had asked for hot water to flush out his system,[4] and remained convinced of Florence's complete innocence.

"[10]: 265  Other commentators remarked ironically that Charles' own counsel had managed to "let the dead man's own 'criminal intimacy' with a prostitute at Maidenhead remain in decent obscurity.

[4] She settled in Southsea, Hampshire, where she bought a property called Lumps Villa, which she renamed Coombe Lodge, and hired a housekeeper, two maids and a coachman.