THE RULES
A code and two seconds
An Irish code of 1777 set out 26 'commandments', and each party chose seconds who tried to settle the dispute and, failing that, arranged the meeting.
Walk through a duelA SHORT HISTORY
Duelling was illegal, and yet gentlemen kept doing it.

1829 a prime minister's duel
172+ duels Duels recorded in the reign of George III
For two centuries a quarrel between gentlemen could end at dawn on a London common. Killing in a duel was formally murder, but courts were lenient. By the mid-1800s public opinion had turned, and the custom faded away.
THE SHORT ANSWER
Three facts frame the story.
Each comes from archive and reference sources.
THE RULES
An Irish code of 1777 set out 26 'commandments', and each party chose seconds who tried to settle the dispute and, failing that, arranged the meeting.
Walk through a duelTHE PLACES
Favourite grounds included Hampstead Heath, Chalk Farm and the commons south of the Thames, where a windmill was a popular meeting point.
The duelling groundsTHE END
Duelling had largely fallen out of favour in England by the mid-19th century. The last known fatal duel in England was in 1852.
See the numbersWALK THROUGH A DUEL
Pick a stage of a 19th-century English duel to see how it worked. The bar shows how close the parties were to actually firing.
Based on King's College London archive exhibition pages and reference accounts of duelling practice.
WHERE AND HOW THEY MET
Duellists needed somewhere near London but out of sight. King's College London's archive describes why certain places were chosen.

Hampstead Heath, Chalk Farm and the commons over Battersea, Putney and Wimbledon were all within easy reach of London.
The grounds were remote enough to avoid interruption. In 1829 the party even jumped a drainage ditch to escape a group of workmen.
In the event of a death, the grounds were conveniently close to roads out of London.
From about 1770 English duellists took up the pistol, and sword duels dwindled. Wealthy men commissioned special cased pairs.
TWO NUMBERS WORTH KNOWING
One figure from the custom's peak,
one on when it finally ended in England.
172+ duels
Duels recorded in the reign of George III
Over 172 duels were recorded in George III's reign, accounting for 69 deaths and 96 people seriously wounded.
THE HEYDAY · KING'S COLLEGE LONDON
1852
Year of the last known fatal duel in England
It was fought near Englefield Green between two French political refugees. The last fatal duel between Englishmen in England was at Browndown, near Gosport, in 1845.
THE END · REFERENCE
In both of those last cases the winner was tried for murder: one was acquitted and the other convicted only of manslaughter, serving seven months in prison.
THE PRIME MINISTER'S DUEL
The Duke of Wellington, then prime minister, was accused in a newspaper letter by the Earl of Winchilsea over Catholic Emancipation. The quarrel led to a duel, and they met at Battersea, then on the edge of London, with seconds and a doctor present.
Wellington fired and missed; Winchilsea fired into the air and then apologised. Newspapers and the public were scandalised that the 'first warrior of England' had risked his life. It was the second and last duel by a sitting prime minister, after Pitt's in 1798.

Questions
No. Killing in a duel was formally judged as murder, but courts were generally lenient because they were sympathetic to the culture of honour.
Seconds carried the challenge, tried to settle the dispute, and if that failed arranged the time, place, weapons and terms of the duel, often aiming to limit the risk of death.
Deliberately firing to miss, for example into the air. It allowed honour to be satisfied, though it could also imply the opponent was not worth shooting.
The last known fatal duel in England was fought in 1852 near Englefield Green between two French refugees. The last fatal duel between Englishmen in England was in 1845.
Yes, two did while in office: William Pitt in 1798 on Putney Heath and the Duke of Wellington at Battersea on 21 March 1829.
Updated
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