The Question Behind the Question
It’s one of the first questions people ask when they begin researching a soldier:
“What were the chances he made it through?”
On the surface, it feels like a numbers game. Look up the casualty rate, apply it to your ancestor, and you’ve got your answer. Except… that’s not how it works. Casualty rates in both the First and Second World Wars are often quoted in sweeping, dramatic figures—“a generation wiped out,” or “far safer than the last war.” Both statements contain truth, but neither tells you much about the individual soldier. Because the reality is this:
Your ancestor’s chances of survival depended far more on where he served, when he served, and what role he held than any headline percentage.
What Counts as a Casualty (and Why It Matters)
Before getting lost in statistics, it’s worth clearing up a fundamental misunderstanding. In military terms, a casualty does not mean death. It includes anyone removed from active service:
* killed,
* wounded,
* missing,
* captured,
* or evacuated through illness.
This matters because when a battalion reports “60% casualties,” it often sounds like near annihilation. In reality, a large proportion of those men may have survived—many even returning to the line weeks or months later.
The First World War: High Risk, But Not Uniformly So
Across the war as a whole, the British Army suffered roughly 700,000 dead and over 1.5 million wounded out of around six million who served. That gives a broad casualty rate in the region of 35–40%. But that figure hides more than it reveals.
Where the Danger Really Sat
For infantry battalions on the Western Front, particularly in 1916–1917, casualty rates could spike dramatically during major offensives such as the Battle of the Somme. Battalions from regiments like the Lancashire Fusiliers, Kings Own Yorkshire Light Infantry, and Royal Fusiliers were all heavily engaged in sustained fighting across this period. In some cases, units could lose half their strength in a matter of days.
Example context:
1st Battalion, Lancashire Fusiliers saw 500 casualties in one assault at Beaumont-Hamel (Somme 1916)
7th Battalion, KOYLI suffered 350 casualties in a very short period (Passchendaele 1917)
4th Battalion, Royal Fusiliers experienced a 40% casualty rate defending Nimy Bridge (Mons, 1914)
And yet, even here, the idea of a unit being “wiped out” is misleading. Reinforcements flowed in constantly, meaning your ancestor’s presence during these peak casualty moments is never guaranteed.
Wounded British soldiers being evacuated from the front line during the Battle of the Somme. Most “casualties” survived—but often at significant cost.
Not All Units Faced the Same War
Even within the same regiment, experience could vary wildly.
A man serving in a Territorial battalion of the Durham Light Infantry might spend long periods rotating in and out of the line, while another in a Service Battalion of the Gloucestershire Regiment could be thrown into major offensives during 1915–1916.
Meanwhile, others served in entirely different roles:
* logistics
* training units
* home defence
The Second World War: Lower Averages, Same Reality
The Second World War saw lower overall casualty rates for British forces, with around 380,000 killed out of approximately five million who served. At first glance, this suggests a much safer conflict. But once again, averages don’t tell the full story.
Units from regiments such as the Royal Scots or Northumberland Fusiliers served across multiple high-risk theatres including North-West Europe, North Africa, and Italy.
Example context:
Some units of the Royal Engineers experienced casualties of 40%+ on D-Day though beach and mine clearance
Some anti-tank batteries of the Royal Artillery had casualty rates of 80% at Gazala in North Africa in 1942
Elements of the Royal Armoured Corps lost 25 out of 50 tanks in single operations in Italy, 1944
Men of the Royal Army Service Corps could lose 50% strength just in supply columns whilst operating in Burma
A soldier landing in Normandy in June 1944 faced a very different level of risk to someone stationed in Britain or serving in a rear-area role.
Why Casualty Rates Alone Don’t Work
This is where many researchers go wrong. They take a general statistic and apply it directly to an individual. But war is not evenly distributed. Again, a soldier advancing through North-West Europe experienced a very different war to one serving in supply or administrative roles behind the lines. Similarly, a man who parachuted behind enemy lines on D-Day faced concentrated, high-risk operations compared to even standard infantry rotations.
So instead of asking:
“What were the chances of survival in the war?”
You should be asking:
“What were the chances in his unit, in that place, at that time?”
How This Links to Service Numbers
A service number can often help identify:
* enlistment period
* type of unit (Regular, Territorial, Service Battalion)
* likely deployment window
From there, you can begin linking a soldier to:
* specific campaigns
* known operational periods
* and importantly, the casualty environment they were part of
If you’re trying to understand what your ancestor actually experienced, you need to go beyond headline figures.
Start with what you know—a service number, a regiment, or even a rough location—and build from there.
Use our tool to uncover likely units, enlistment periods, and the kind of war your ancestor actually faced.