From 1939 to 1945, World War 2 ravaged the world. It was the bloodiest conflict in history, with up to eighty million people in total being killed, which was more than double the total that perished during World War I (which was supposed to be the war that ended all wars).
Simply put, casualties and bloodshed have never been seen either before or after World War II.
Here are the bloodiest battles of the conflict:
#1 The Battle of Stalingrad

The Battle of Stalingrad was both the largest battle in human history in terms of the number of men who fought, in addition to the bloodiest battle in terms of sheer casualties as well. In 1942, the Germans had lost the Battle of Moscow the previous winter. Rather than continue their offensive, they decided to strike south towards Stalingrad in order to gain control of the Caucasus oil reserves.
The German Luftwaffe bombed Stalingrad into submission while the 6th Army surged forward, flanked by the Italian, Romanian, and Hungarian armies. Some of the fiercest combat of World War II took place in the rubble of Stalingrad. The Soviet resistance was fierce, but the 6th Army pushed them back to the Volga River.
In December, just as the Germans were on the verge of victory, outside Soviet armies launched counteroffensives on the flanking Italian, Hungarian, and Romanian armies. These armies broke apart and the Soviets surrounded the 6th Army in Stalingrad before closing in from all sides. Hitler ordered the 6th Army to hold out and be resupplied by the Luftwaffe while outside forces would attempt to break them out.
The Soviets were able to successfully shoot down enough aircraft that the 6th Army could not be resupplied while also stopping the outside German offensive. A month later, the battered 6th Army, out of food, water, ammunition, and trapped in the freezing cold in summer clothing, was forced to surrender.
The Soviets sustained nearly 1,200,000 casualties at Stalingrad, of whom nearly 500,000 were killed. The Axis lost over 800,000 men, including the entire German 6th Army, which was a blow they would never fully recover from.
#2 Battle of Berlin

The Battle of Berlin was the final battle on the Eastern Front in World War 2. The Soviet forces advanced to only a few miles short of Berlin, where the front lines stabilized. By now, the Germans were in a desperate situation. They had used up the last of their reserves, most of the men in their armies were either very young or old, and they were down to the last of their tanks, artillery, and ammunition.
When the battle commenced in mid-April, around 2.5 million Soviet soldiers and 6,000 tanks swarmed forward against 750,000 German soldiers and 1,500 tanks and armored vehicles. The Germans held strong at Seelow Heights, where they held the high ground, for several days but were eventually pushed back into the city.
The Soviets then surrounded the city and attacked it from all sides. Some of the most brutal hand-to-hand combat since Stalingrad took place in the ruins, but the Soviet advanced was relentless. Hitler desperately ordered counterattacks in an attempt to save the city, but these never materialized because the units he wanted to attack existed only on paper.
Finally, Hitler committed suicide on April 30th, and a few days later the German garrison surrendered. The Germans suffered around 100,000 dead and 220,000 wounded. The Soviets suffered 81,000 dead and 280,000 wounded.
#3 Battle of Iwo Jima

The Battle of Iwo Jima was one of the most famous battles in World War II, largely due to the famous photograph of the American soldiers raising the flag that was taken on the island and later became the subject of the film and book “Flags of our Fathers.” The Americans invaded the island with the intention of using it as an airbase to bomb Japan.
The Japanese had 21,000 troops to defend against more than 110,000 American attackers. The Japanese deliberately planned the battle to inflict as many American casualties as possible. To this end, they allowed the Americans to land on the beach in masse before opening up with machine gun, mortar, and artillery fire.
The beachhead was turned into a bloodbath, but the American forces managed to fight their way up Mt. Suribachi. Once the mountain had been taken, the Americans then swept over the rest of the island. Bitter fighting continued for over a month.
In the end, virtually all of the 21,000 Japanese garrison was wiped out, with only 216 taken prisoner. The Americans lost 6,800 killed and 19,200 wounded. This was one of the few battles of the Pacific where the overall American casualties were higher than the overall Japanese losses.
#4 Battle of the Bulge

The Battle of the Bulge was fought in December of 1944 and January of 1945. In the battle, Germany committed the last of their reserves in an attempt to smash through the American forces in the Ardennes forces in Europe. The goal was to drive all the way to Antwerp and split the British and American forces in two.
Armed with their formidable Tiger and Panther tanks, the Germans were initially very successful in the opening days of the offensive and caught the Americans completely off guard. Several American pockets of soldiers became isolated and cut off, and were forced to fight on their own against numerically superior German forces.
Eventually, the Germans’ fuel supplies began to run out, and American reinforcements begin to arrive en masse. The Germans were then pushed back to their original starting lines within a month. The battle was a severe blow to Germany, which fell far short of its objectives and had wasted the last of its reserves. The battle was also the bloodiest battle the Americans fought in World War II. Total American casualties were nearly 90,000, while the Germans lost anywhere from 65,000 to 100,000 depending on estimates.
#5 Battle of Okinawa

The Battle of Okinawa, fought in mid-1945 between the United States and the Japanese, was one of the bloodiest battles in the Pacific theater of war. The Americans needed to take Okinawa for the airfields to aid in the bombing of the Japanese islands and as a base for the upcoming planned invasion of the home isalnds. The Japanese dispatched their largest warship, Yamato, in a desperate attempt to stop the American ships but it was sunk.
Over 250,000 American troops landed in the island to engage the 96,000 Japanese defenders. The fighting was fierce and brutal, as the Japanese stubbornly refused to give ground and fought to the death. Only a few survivors surrendered.
By the end of the battle, more than 20,000 American soldiers were killed and 55,000 were wounded. Only 7,000 Japanese surrendered, while the rest of the garrison was wiped out.
#6 The Battle of Kursk

The Battle of Kursk is known for being the largest tank battle in history. In mid-1943, the Soviet forces had decisively defeated the Germans at the Battle of Stalingrad. However, contrary to what most people think, the Battle of Stalingrad was not the real turning point on the Eastern Front. This is because the German forces still held the initiative and were capable of launching major offensives across the front. Furthermore, the Soviet advance had been halted after Kursk, and the Germans counterattacked and retook the city of Kharkov, inflicting heavy Soviet casualties in the process.
By the summer of 1943, the front lines had stabilized and the Germans were preparing for a renewed offensive. The Soviet forces had created a salient in the front lines around the town of Kursk, and Hitler hoped to attack this salient from the north and the south and trap and destroy the Soviet armies inside. However, Soviet forces gained knowledge of the attack from British intelligence, and spent months constructing defensive fortifications and pouring forces into the area in anticipation of the assault.
The battle began in July and the Germans initially made strong headway, destroying much of the Soviet armor, but they fell short of their objectives. Soviet reserves were then thrown into the battle to blunt the German advance. Thousands of Soviet and German tanks fanned out across the plains and engaged in battle at Prokhorovka, the largest tank battle to date. When the Allied forces landed in Sicily, Hitler decided to call off the offensive to divert men and resources back to the Italian front.
All in all, the Soviets lost significantly more men and tanks than the Germans did, but they could replace their losses whereas the Germans could not. The Germans suffered over 110,000 men and 1,200 tanks and assault guns in the entire operation, while the Soviets sustained over 800,000 casualties and 6,000 tanks.
#7 The Battle of Moscow

The Battle of Moscow was supposed to be the battle that would end the Eastern Front in World War II, but the German army was stopped by the mud and winter. In fall of 1941, the Wehrmacht was closing in on Moscow and the Soviet forces were desperate. They had lost more than half of their initial strength, and the Germans appeared unbeatable.
Fortunately, the winter set in and greatly slowed down the Germans, who lacked winter clothing and were unprepared for the freezing temperatures. Then, when it became clear that Japan would not invade from Siberia, Stalin was able to redeploy the vast forces he had reserved there and sent them smashing in against the worn down Germans.
The Germans were forced back, despite being so close to Moscow that they could see the Kremlin. Eventually, the Soviet offenses petered out as well and the frontlines stabilized, where they would remain until the Germans would attempt to take Stalingrad in the next year. The Soviets ended up with over 1,000,000 dead and wounded during the battle, while the Germans suffered 171,000 killed.