The 5 most famous love affairs and infidelities in history, seen by an investigator

This is the third article in a short series. In the first I wrote about why people cheat, and why infidelity no longer matters in a Swiss divorce. In the second I looked for the origin of a universal image: why the betrayed are said to "wear horns".

Here I look back at history. From Helen of Troy onwards, infidelity has changed the fate of families, dynasties and even wars. I have chosen five of the most celebrated cases and reread them through the eyes of my profession: what is documented, what is legend, and what the evidence was really worth. More than once, the answer is surprising.

1. Paolo and Francesca (Rimini, 1283–1286)

The facts

Francesca da Polenta, a noblewoman from Ravenna, married Giovanni Malatesta, known as Gianciotto, son of the lord of Rimini, around 1275. It was a political marriage, meant to end a rivalry between the two families. In Rimini, Francesca began an affair with her husband's younger brother, Paolo, himself married. According to reconstructions, the affair lasted years. Gianciotto caught them and killed them both, between 1283 and 1286 (Wikipedia).

The literary testimony

What we know we owe above all to Dante, who in Canto V of the Inferno places Francesca among the lustful and gives her a voice. It is she who tells how reading the book of Lancelot and Guinevere, another famous tale of betrayal, made them fall in love. And hers is one of the most famous lines in Italian literature: "Love led us on to one death."

Dante probably learned the story from Francesca's nephew, Guido Novello da Polenta, who hosted him in Ravenna in his final years.

Where fact ends and story begins

Later, Giovanni Boccaccio added a romantic detail: Francesca was supposedly tricked into believing she was marrying the handsome Paolo instead of his brother. Historians treat this version with great suspicion: Boccaccio was born decades after the events, nobody before him reports it, and Francesca certainly knew both brothers.

The lesson for an investigator: the further from the facts, the richer the stories become. And the most beautiful details are often the least reliable.

2. Anne Boleyn (London, 1536)

The accusation

In spring 1536 Anne Boleyn, second wife of Henry VIII of England, was arrested and accused of adultery with several men of the court, of incest with her brother George and of plotting against the king. The musician Mark Smeaton confessed, possibly under torture or a promise of freedom. The others declared themselves innocent. Anne was convicted and beheaded at the Tower of London on 19 May 1536; her brother and the other accused had been executed two days earlier (Wikipedia).

The evidence, or rather its absence

Most historians consider the charges largely unfounded, and the trial a legal travesty. The context explains a great deal: Anne had not given the king the male heir he wanted, and for months Henry had been courting one of her ladies-in-waiting, Jane Seymour, whom he married days after the execution.

An infidelity in reverse

It is the most disturbing case on the list, because it turns the perspective around: here the infidelity probably never happened, but the accusation served to get rid of an inconvenient wife. A confession obtained under pressure, compliant testimony, a court that already knows which verdict it must deliver.

The lesson for an investigator: an accusation is not evidence, and a forced confession is worth nothing. That is why today, in Switzerland, the way evidence is gathered matters as much as the evidence itself.

3. Marie Antoinette and Count Fersen (1774–1793)

The suspicion

For more than two centuries historians and biographers have wondered whether Marie Antoinette, queen of France, had an affair with the Swedish count Axel von Fersen, an officer and her devoted ally, who in 1791 organised the royal family's escape attempt stopped at Varennes. The letters between them existed, but in many places they had been blotted out with dense ink.

The scientific investigation

Here the story becomes a true laboratory case. A team of French researchers from the Centre for Research on Conservation, led by chemist Anne Michelin, analysed 15 letters from the queen to Fersen with spectroscopy techniques able to distinguish the composition of the writing ink from the ink used to cover the text. In eight letters they were able to read the censored parts (NPR).

Two findings. First: the covered passages were mainly the intimate and affectionate ones, while political passages had been left readable, with words such as "love", "madly", "adore". Second, even more interesting: by comparing the inks, the researchers concluded that the letters were in all likelihood censored by Fersen himself.

What they really prove

The temptation is to say: case closed. But the researcher herself urges caution: the letters also discuss politics and strategy at a dramatic moment, and the affectionate language of the eighteenth century does not automatically equal a physical relationship.

The lesson for an investigator: new and spectacular evidence must still be interpreted in context. It is the same logic I described with the Enigma machine: an encrypted or censored text reveals a great deal through what someone wanted to hide.

4. Lord Nelson and Lady Hamilton (Naples and London, 1798–1805)

History's most public triangle

Emma Hamilton, wife of the British envoy in Naples, Sir William Hamilton, met Admiral Horatio Nelson in September 1793. The affair began after Nelson's return to Naples in September 1798, just after the victory of the Nile. On 29 January 1801 their daughter, Horatia, was born.

The peculiarity is that it was not a hidden affair. From November 1800, back in England, Nelson, Emma and Sir William lived openly together, first in London and then at Merton Place, bought by Nelson in 1801. The public was fascinated and scandalised in equal measure. Sir William, though he privately reproached his wife, stayed with them until his death in 1803 (Wikipedia).

The ending

Nelson died at the Battle of Trafalgar on 21 October 1805. In a codicil he asked the government to provide for Emma. The request was not granted. Emma, buried in debt, spent time within the rules of the debtors' prison, fled to Calais with her daughter and died there in poverty on 15 January 1815.

The lesson for an investigator: the best-documented cases are often the ones nobody tried to hide. And society, then as now, forgave the national hero what it did not forgive the woman.

5. Napoleon and Joséphine (Paris, 1796–1810)

A mutual infidelity

Napoleon Bonaparte married Joséphine de Beauharnais on 9 March 1796. Soon after, while he was busy with the Italian campaign, she began an affair with a young hussar officer, Hippolyte Charles. The rumours reached Napoleon, who was deeply hurt. During the Egyptian campaign in 1798, it was his turn to begin an affair with Pauline Fourès, an officer's wife nicknamed "Napoleon's Cleopatra" (Wikipedia).

The divorce, which had nothing to do with infidelity

The marriage survived the mutual infidelities. What ended it was another reason: Joséphine could not give Napoleon the heir the empire needed. On 30 November 1809 he told her of his decision, "in the interest of France"; the divorce was finalised on 10 January 1810.

The bond did not break entirely, though. According to tradition, on his deathbed on St Helena, Joséphine's name was among Napoleon's last words.

The lesson for an investigator: infidelity is rarely the real reason a marriage ends. More often it is a symptom, or a detail within a more complex story. That is what contemporary research says too, as I described in the first article in this series.

A more recent case

The twentieth century added its own famous cases, lived under the media spotlight. The best known is probably that of Prince Charles and Princess Diana: in a 1994 television interview Charles admitted being unfaithful once the marriage had broken down, and the following year Diana told the BBC the famous line "there were three of us in this marriage". A case unlike all the previous ones: here the confessions came on television, in front of millions of people.

What five centuries of infidelity teach us

Lined up, these cases tell us three things that still hold today.

Evidence is never neutral. Dante tells Francesca's story through her own voice; Anne Boleyn's trial builds the evidence to reach a verdict already written; Fersen carefully erases exactly the most intimate lines. Whoever gathers or keeps a document always chooses what to show.

Time embellishes stories. The more famous a story, the more it fills with invented details. Separating facts from legends means going back to the sources, as we did with the origin of the cuckold's horns.

Infidelity is rarely the whole story. Behind every case there are political marriages, missing heirs, reasons of state, loneliness. It is the same conclusion research on the motives for infidelity reaches.

These are the same principles I apply in my work, whether I am reconstructing a historical event through historical research or someone asks me to shed light on a suspicion today. With one important difference from the past: today evidence is gathered within the law, and the truth is not presumed, it is proven.