Time and technology have not changed mortality in battle until only very recently.
Looking at the major battles of history will show that the progression of time seems to have not had a significant effect how many men die in a particular battle. What it will show, however, is that what seems much more important is the match-up of enemies in terms of strength, battlefield logistics and tactical advantages. Throw in other factors like if a particular army on any given day is even capable of retreating drastically affects the numbers and is not dependent on what era the battle was fought it. Where time and technology have greatly affected the number of men who die is related to those who would have otherwise passed a few days later or on the roads to and from battle.
Historically many, many more warriors have died as the result of poor medical care, starvation or exposure than have died at the end of enemy weapons. It has really only been in the last 300 years or so that significant enough advances in medicine have had a drastic effect on the survival of a soldier. Add into this logistical capabilities have evolved better and better ways to get more warriors, food, medicine and supplies to the battle lines.
I’ll take a second to also note that historically there has been little distinction in reporting battlefield casualties from fatalities. Fatality refers to an actual death, while casualty refers to either death or severe injury. Since even very minor wounds often would result in death due to little knowledge of the human body or as a result of infection, to get injured was a much more serious thing in wars until just after the American Civil and Napoleonic Wars. Historians of those eras either didn’t or couldn’t record the differences as well as we can today. This also muddles the facts when we try to compare wars of different times. An example of this would be to compare the Battle of Antietam, the bloodiest day in American military history, to the Battle of Cannae, one of the most crushing defeats to the Roman Empire. At Antietam we have, however, a total fatality count of only 2% while at Cannae it can be reported that there was over 53% casualty rate. From this we can see what likely has happened is that most of those who died at Antietam did so after the battle and that most of its history probably refers to death and injury, while Cannae would suggest that there is little record differentiating between deaths and injuries. While it was a gruesome battle, particularly for the Romans, I find it hard to believe that a whole half of the battlefield died in the fight.
From these battles it seems that two factors actually have much more effect than the era of the battle on who and how many will die. What seems to affect the mortality rate more than any other factor is the presence of overwhelming force and the availability of retreat.
Presence of overwhelming force:
This is actually a good thing. In many battles where one side held a clear advantage in numbers, equipment, and leadership, the total mortality was surprising low. I contribute this to lower total casualties because the winner doesn’t lose as many men, the loser breaking and retreating early and the concept of surrender, which is much more common than many think. To cite battles by Alexander, by the time he marched into India, a majority, or at least a sizable minority of his men were made of Persian soldiers who were once his enemies that were now absorbed into his army. Many of these were mercenaries, but many simply served the new ruler of Persia. This would not have made many of his battles after he left Greece possible, had the Macedonians killed as many as they could, leaving no one to recruit later.
Another example of presence of overwhelming force would be the invasion of Iraq by the United States and Coalition forces in March of 2003. In that series of engagements strategic pin-point bombing destroyed the Iraqi military’s communication network and much of their leadership. More traditional bombings took out bases, aerial and ground assets, leaving only scattered infantry. With combined arms capabilities, Coalition forces had at their disposal the ability for a single soldier to call in airstrikes, mortar and artillery fire, more infantry, or other specialty capabilities for any enemy they encountered. This, along with the fact that even without these abilities, the individual United States infantry troop has better training, combat tactics, gear and experience than even elite troops of almost any other nation. What ended up taking place during the invasion was that a numerically weaker force of around 265,000 annihilated a force of about 1,190,000 suffering only 172 losses to the Iraqi losing nearly 30,000 in the span of only about three months. That is a kill ratio of 175:1. What this amounts to is the most successful invasion in history with more ground captured and fewer losses than could ever be expected. In spite of this massive win, the total casualty percentage was around 2% overall. It was truly an amazing accomplishment. That isn’t to say that anyone believes the next 8 years went all that well, though.
An example where overwhelming force was not present would be the battle of Yarmouk in 636. This was a face-off of two extremely powerful armies of the time, each believing, reasonably well that they could win, the Eastern Roman Byzantines and the Rashidun Caliphate. The battle lasted for six days, a great deal of time for a pitched battle. The fighting was more or less even until on the sixth day, the Roman line broke, fled and were massacred. The fact that they were so evenly matched lead to very high casualties, in this case 14% for the winner and 45% for the losing side.
From my findings, overwhelming strength seems to be the most merciful way to fight a war. It brings a swift end to a fight, keeps allied casualties down and encourages enemy forces to flee rather than be annihilated. It may seem obvious, but far too often forces will meet with just enough to maybe win and result in catastrophic losses.
Ability to Retreat
Another factor important to many battles is the ability for the loser to get away. Most battles ended in some level of an organized retreat and most people who fought survived. Where this is ability to run away is somehow prevented you see the most massive of casualties. Once again I will refer to Yarmouk and Cannae. At Yarmouk when the Romans finally broke they were greeted with only a series of rivers behind them. Many were then unable to retreat and then massacred by the Islamic army. At Cannae, a brilliant general was able to utilize his units to completely envelope the enemy army. This meant that the Carthaginian forces had to keep fighting until every last Roman in the envelopment was killed. It cost the Carthaginians 16% of their forces, but the Romans suffered a 75% casualty rate. Had either of these armies had the ability to disengage from the battle they had already lost, we would have seen much fewer losses.
These are a few of the things to consider when viewing the history of warfare across such a long span of history. That said I have tried to collect enough resources to answer the question as best I can as a hobbyist.
Greek Battles
Battle of Marathon, 490 BC
Total Combatants: 35000
Total Casualties: 6603
Total Casualty%: 18.87%
This is a major battle involving the Greeks and Persians. According to historical records this showed the Greeks conflicting massive losses to the Persians due to their use of more advanced equipment, training, tactics and a more motivated population of military. In that battle they inflicted losses of more than 6000 on the Persians while only losing a few hundred themselves.
Battles of Alexander the Great
Battle of Gaugamela, 331 BC
Total Combatants: 122000
Total Casualties: 48100
Total Casualty%: 39.43
The Battle of Gaugamela took place in 331 BC between Alexander the Great and Darius III of Persia. The battle resulted in a decisive victory for the Macedonians and led to the fall of the Persian Empire. It is another battle where we see a smaller force, with much better tactics, logistical support, training, equipment and motivation soundly defeat a much larger force.
Roman Battles
Battle of Cannae 216BC
Total Combatants: 136400
Total Casualties: 73000
Total Casualty%: 53.42
Cannae was one of the most crushing defeats the Romans ever experienced. The greatest feat in this battle was the leadership of Hannibal. He marched an army of mostly mercenaries gathered from all over Northern Africa and what is now modern Spain and France through the Alps into the heart of Rome. He led an incredibly diverse variety of warriors, many speaking different languages and vastly different from his own Carthaginian culture, into a highly flexible force combining the unique capabilities of each unit into one amazing strategy. By the end of the battle the Romans were completely surrounded and cut down one by one suffering more than 65,000 casualties.
Crusades
Battle of Yarmouk 636
Total Combatants: 85000
Total Casualties: 29875
Total Casualty%: 35.15
The Battle of Yarmouk was a major battle between the Muslim Arab forces of the Rashidun Caliphate and the armies of the Eastern Roman Empire that I have never heard of before writing this answer. It was extremely important, however, in that it ushered in the Islamic Arabs as the new power, filling the power vacuum as Rome’s time was coming to an end.
Middle Ages
Battle of Falkirk 1298
Total Combatants: 21000
Total Casualties: 3000
Total Casualty%: 14.29
Here Scots led by William Wallace are soundly defeated by Edward the First as their pikemen are arranged into a defensive formation to guard against cavalry charge and are in turn showered by archery fire.
Battle of Grunwald 1410
Total Combatants: 49000
Total Casualties: 12500
Total Casualty%: 25.51
Here an alliance of Polish and Lithuanian forces defeated the Teutonic Knights and brought about the end of the Northern Crusades.
Battle of Agincourt 1415
Total Combatants: 31500
Total Casualties: 8612
Total Casualty%: 27.34
Here English longbowmen secure a massive victory by taking advantage of a confused and disorganized force marching through thick mud. Environmental factors played the largest part of this battle, aiding the archers in staying safely away from the fighting to break up enemy formations and kill many enemy forces before they could reach the fight.
Early Modern Era
Battle of Flodden 1513
Total Combatants: 60000
Total Casualties:12500
Total Casualty%: 20.83
This was the largest battle between the Scots and the English. This was a crushing loss for the Scots, resulting in the loss of their king.
Battle of Vienna 1683
Total Combatants: 305700
Total Casualties: 46500
Total Casualty%: 15.21
This is one of the most important battles of history. This marked the end of Islamic growth in Europe from military victories. An alliance of Christian forces gathered together enough to stop a much larger Ottoman force. The Ottomans would not recover from that loss and their military prowess would eventually fade until they were finally broken up in the 20th century.
American Revolution*
Battles of Saratoga 1777
Total Combatants: 21600
Total Fatalities: 530
Total Fatality%: 2.45
This was an important battle for the Americans though its numbers are not that impressive for a post like this. See my note at the bottom for reasons I think American battles experience such low casualties. Saratoga marked a turning point in the American Revolution in favor of the Americans. What is probably the result of the low casualties were the civility of forces, the ability to retreat and the practice of taking prisoners, more than 2000 English prisoners in all.
Napoleonic wars
Battle of Austerlitz 1805
Total Combatants: 157000
Total Casualties: 16305
Total Casualty%: 10.39%
Here Napoleon led his French Army to soundly defeat an alliance of Russian and Austrian forces. His tactics and strategies in the battle were brilliant and gave the battle and the leader himself legendary status. This battle is often considered one of the greatest executed in history and on par with Gaugamela and Cannae.
Battle of Waterloo 1815
Total Combatants: 190000
Total Casualties: 75000
Total Casualty%: 39.47
Overconfident from Austerlitz and other victories, Napoleon doesn’t factor in the environmental factors and the importance of combat logistics. He suffers greatly and even more so in the retreat back home.
American Civil War*
Battle of Antietam 1862
Total Combatants: 113500
Total Fatalities: 3654
Total Fatality% 3.22
The Battle of Antietam is considered the bloodiest single day in American history. Once again, the numbers above do not give a full image of the battle. It is difficult to say if these estimates include battle losses or losses later from wounds.
Battle of Gettysburg 1863
Total Combatants: 165620
Total Fatalities: 7863
Total Fatality%: 4.75
Gettysburg is much the same story. Here we actually have very good records of how many died at the battle, how many were wounded, and how many went missing. This battle was considered the turning point of the war and resulted in the North securing vital strategic points and resources that would eventually starve out the South from a logistical and economic standpoint.
World War I
Battle of the Argonne Forest 1918
Total Combatants: 740000
Total Casualties: 292000
Total Casualty%: 39.48
While Antietam would be considered the bloodiest day, Argonne Forest is considered the single bloodiest battle in American history. It is hard to be considered a single battle, however, since it stretched two months and along the entire Western front. It was the final offensive by Allied forces and ended in the November armistice bringing about the end of that war. The lethality of this battle was due to the exponential growth in military technology while holding to tactics and strategies that were severely outdated. For the first time air power played a significant role in combat operations. Machine guns had evolved to the point that they were now reliable and afforded a single lucky soldier the ability to mow down entire platoons in seconds. Artillery was now able to fire from miles away reliably. Artillery has accounted for more battlefield deaths in World War I and II than any other source combined. World War I was one of the most lethal wars in history because it combined new technologies with old tactics for devastating effects.
World War II
Normandy landings 1944
Total Combatants: 3052299
Total Casualties: 556323
Total Casualty%: 18.23
Normandy was the beginning of the end for World War II in Europe. It was the single largest military operation in world history. Thousands of ships moved millions of men to swarm the a length of the French northern coast as long as the coastline of Texas. Hundreds of thousands were lost in the attempt to defend it and on the side of those securing a foothold.
Battle of Okinawa 1945
Total Combatants: 303000
Total Casualties: 107513
Total Casualty%: 35.48
This was one of the last major battles of World War II. The battle was important because with the capture of Okinawa, the American forces would be able to easily reach mainland Japan with aerial bombers. Nearing the end of the war this battle was important because of the massive losses experienced by the Japanese defenders, many refusing to surrender and instead volunteering for kamikaze suicide attacks. In the end the Japanese lost more than 90,000 men or nearly 80% of their defense force for the island.
Recent Changes in Warfare
More recently we have seen a significant shift in how many casualties result from a battle. In the Yom Kippur War and the War in Iraq 2003-2011, you see that battle in the modern era is actually much less about killing and much more about securing or destroying vital asset to enemy and ending their ability to fight. This was true for all other wars as well, but never before have armaments such as the B-2 Spirit Bomber, F-22 Raptor, Tomahawk cruise missile or the Javalin Missile system been available. Now the ability to destroy vital targets and prevent actual soldiers from even engaging in a fight is the preferred method of engagement. The ability to strike from a distance has actually done more to end battles quicker and prevent the deaths of many a modern warrior. This level of technological prowess doesn’t guarantee an easy victory and as always is still vulnerable to guerrilla warfare, terrorism and other forms of non-conventional battle tactics. For the purposes of this question though, the modern era is one where perhaps we have seen the last of massive losses of warriors in single battles.
Yom Kippur War
Yom Kippur War 1973
Total Combatants:1125000
Total Casualties: 15950
Total Casualty%: 1.42
The Yom Kippur War was a war between a coalition of Arab states against Israel. The war saw numerous small engagements over a very short time. Early strikes against the Israelis meant that the Israeli feeling of invulnerability was shattered. After regrouping they gained the high ground and at the end of engagements had forces ready to take both the cities of Damascus and Cairo.
Iraq War
2003 invasion of Iraq
Total Combatants: 1455000
Total Casualties: 29672
Total Casualty%: 2.04
As mentioned before, the invasion of Iraq was one of the single greatest engagements in history in terms of land taken and number of allies lost in battle. It was also important in that the speed and lethality of the Coalition forces made it extremely efficient and allowed for a minimal amount of enemy forces to be killed. It stands, however, as battles such as Austerlitz in 1805 and Cannae in 216 BC that without a good plan for after the battle, political incompetence can lose a war started with the greatest of battles.
* American battles surprised me that the casualties were so low. As mentioned before, this may be due to good modern efforts to distinguish between dead and wounded, as well as discounting for the dead who died shortly after. Another theory is that it might lend to the idea that American wars like the American Revolutionary and Civil Wars actually were quite civil. Close relations between the Colonials and English and the North and South may have caused a much more “peaceful” type of war than what could be expected when completely foreign powers meet in battle. The practice of care given to prisoners rather than killing everyone most likely was a huge factor in this as well. A third possibility may be that this was the beginning to the American approach to limit American casualties. The American practice is to send in more than enough men with massive logistical support and focus on strategic wins that damage the ability to make more than the actual warriors themselves. Other cultures haven’t historically shown this as their priority.
**I want it known that to come up with these estimations I wasn’t always afforded perfect records. To keep things simple most of the statistics can be found by following links to the Wikipedia pages on the wars, campaigns and battles I have provided. Where numerous sources disagree I tried to use my best judgement and sometimes averaged the most reliable sources. That said, I am probably wrong, but ballpark on many of my figures. I freely accept this, but just wanted to make a clear representation of the big picture of battlefield mortality over history and not on the details of each individual battle. Let’s face facts, this answer got long enough.
I would really love casualty counts for Battle of Adrianople, Battle of the Catalaunian Plains and many other battles. It was horribly difficult to also find good assessments for any of the major battles in Asia. I would really love good information for them since their forces and battles were astronomical. Please suggest if you find information for other great battles.
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