I have done a bit of research and it seems the Somme, Towton and maybe Bannockburn are up there? Any more to throw into the mix?

Great site by the way!

  • 1
    You would probably have to add Marston Moor and Flodden to the Somme, Towton and Bannockburn.
    – CGCampbell
    Apr 4, 2016 at 18:50
  • 1
    How can I forget Flodden! I am a Scot as well! Thanks. Flodden was around 20,000 casualties if I can remember my school days correctly?
    – Paul Laing
    Apr 4, 2016 at 18:53
  • 4
    Despite historical importance, the bloodiest medieval battles are tiny compared with a few days casualties of any World War.
    – Pere
    Apr 13, 2018 at 23:34
  • @Pere I think we can limit that to World War I. The total British KIA during World War II is estimated at 383,700, and there are at least 3 battles during the first war with comparable British casualties.
    – Spencer
    Dec 15, 2019 at 22:06
  • @Pere possibly not when you conisder relative sizes of the forces involved, and the population at the time and the effects of those loss on that population. Dec 16, 2019 at 8:28

2 Answers 2


List of battles by casualties

I have made a list using this wikipedia article named List of battles by casualties and have simply removed the ones involving Brits and put them in to order from one to five, and added one extra.

One to five

  1. Battle of the Somme. 1 July 1916 – 18 November 1916. 420,000 British casualties
  2. Spring offensive. 21 March – 18 July 1918. 418,374 British casualties.
  3. Battle of Passchendaele. 31 July – 10 November 1917. Approx 300,000 British casualties
  4. Battle of Watling street. 61 AD. 80,000 British casualties.
  5. Burma campaign. 14 December 1941 – 13 September 1945. 28,878 British killed and missing.
  6. Battle of Towton. 29 March 1461. 28,000 disputed casualties

You might want to consider following battles as bloodiest for British armies. Please note I am not considering a day-by-day casualties count, but the total casualties for a battle.

  • The Somme battle: classic, you cite that one already. A long and bloody battle, with I think some top day by day casualties count
  • Battle of Ypres (WW1 as well)
  • German Michael offensive on British forces
  • Battle of Lys, a few days after the Michael offensive
  • Battle of Normandy: long and blooy battle, because the British forces, as well as Commonwealth forces, handled so much offensives against German forces
  • Market Garden operation (Arnhem battle) : heavy losses on airborne and armoured forces

Some good candidates:

  • I suspect the Pedestal operation has suffered very high casualties, considering the high number of sunk ships and the inhability to control the battlefield after the fight
  • Battle of Gandamak, 1st war of Afghanistan: a good candidate for the Asiatic zone, with 15 000 casualties including about 4 500 soldiers.
  • 1917 year of air battles: a very hard year for the Royal Air Force, with numerous losses. A lot of deaths for air forces, but not as a number
  • Raid on Nuremberg: A lot of deaths for air forces, but not as a number
  • Wild guesses are not appreciated. Operation Pedestal, for example, has a high estimate of 550 killed -- barely a skirmish by World War I standards.
    – Mark
    Mar 10, 2021 at 3:21

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