The graphic above is from Poppyfield.org.  You can find the interactive version here.  Designed by Valentina D’Efilippo with coding by Nicolas Pigelet:

Each poppy depicts a war since the 1900. The stem grows from the year when the war started and the poppy flowers in the year the war ended. Its size shows the number of deaths and the variation of colour represents the areas involved.

It is, as they note, a work in progress (sadly, that’s true in both senses of the phrase).

These grim tabulations don’t tell the whole statistical story, however, because they take no account of those wounded (and the inclusion of civilian as well as combatant casualties further complicates the picture).  As I’ve noted before, Tanisha Fazal provides an essential qualification to the Whiggish view of war and violence peddled by Steven Pinker and others:

Tanisha’s argument hinges on the reliance on ‘battle deaths’ as an index of the incidence of war; these statistics are a minefield of their own, though they are used by most of the major databases, but Tanisha argues that many contemporary wars have been distinguished by a diminution in battle deaths and a marked increase in the numbers of wounded who now survive injuries that would previously have killed them.

John McCrae, the author of ‘In Flanders Fields’ – whose opening lines are among the most famous of First World War poetry: ‘In Flanders fields the poppies blow/Between the crosses, row on row’ – knew that at first hand.  He composed the poem after the Second Battle of Ypres in the spring of 1915 (below), and he wrote to his mother:

‘The general impression in my mind is of a nightmare. We have been in the most bitter of fights. For seventeen days and seventeen nights none of us have had our clothes off, nor our boots even, except occasionally. In all that time while I was awake, gunfire and rifle fire never ceased for sixty seconds…  And behind it all was the constant background of the sights of the dead, the wounded, the maimed…’

But, as John Keegan noted in The face of battle, in most military histories the ‘wounded apparently dematerialize as soon as they are struck down…’  Keegan was writing about General Sir William Napier’s account of the battle of Albuera in 1811, but the disappearing trick is still being performed more than two centuries later.