Some of the world's most-loved brands have dark pasts. Despite their high-quality products and slick marketing, many companies that you know and possibly buy from have ties to ugly periods in history.

From a human and military perspective, the horrors of the Nazis in World War 2 are universally recognized. However, few realize that certain companies inside and outside Germany continued doing business with the Nazis at the height of their atrocities.

Some brands that collaborated with the nazis were conceived in Germany during Hitler's reign. Other foreign companies shamefully found ways to continue trading, even against their own country's war interests.

While you might forgive a few of these companies for simply doing business, the active role of others in facilitating the Holocaust is undoubtedly unforgivable. The worst offenders used slave labor from concentration camps to manufacture their products.

This list of Nazi collaborator brands might shock you and make you rethink your past purchases. Today, all of these brands are doing better than ever. The discovery of these ugly truths hasn't dented their reputations much, even though very few have apologized.

1. Coca-Cola: The Most Famous Among Brands That Collaborated With The Nazis

Coke's reputation for unhealthy sugary drinks doesn't come close to its sickening greed in Nazi Germany. The company had enjoyed massive popularity throughout Hitler's early reign thanks to efforts to promote it as a pro-German product.

However, supply issues at the beginning of the war meant that the syrup needed to manufacture the drink couldn't reach Germany. So, the German division of Coca-Cola created an entirely new drink called Fanta for the German market.

Naturally, this was a tremendous success, and the drink became almost as famous as the signature Coca-Cola beverage. At the same time, this company provided American soldiers with drinks, so the conflict was very profitable.

When the war was over, Coca-Cola continued as usual in Germany. This is one of the most recognizable brands that collaborated with the nazis.

2. Hugo Boss: Fashionable Nazi Collaborator Brand

The luxury clothing and fashion brand has its roots much closer to Nazi Germany than Coca-Cola. The founder, also named Hugo Boss, became a member of the Nazi party in the 1920s and donated money to the SS. His company started manufacturing garments for Hitler's party as early as 1924 and continued so throughout the 1930s, both for the Hitler Youth and armed forces.

The outbreak of war increased the demand for Hugo Boss clothing along with profits. To keep up with the request, the firm had to rely on prisoners of war and concentration camp victims to increase production output.

Sadly, many laborers were simply sent back to the concentration camps after their hard work.

Hugo Boss died in 1948, but the Nazi collaborator brand went from strength to strength after its appalling role in the war. In their defense, the business did pay some reparations in 1999 to families of Holocaust survivors.

3. Volkswagen: One Of The First Brands That Collaborated With The Nazis

Like Hugo Boss, the origins of Volkswagen can be traced to Germany. The difference is that the Führer himself can take some credit for the stylish Volkswagen beetle since the company was his brainchild.

Hitler personally commissioned the director of Porsche (Ferdinand Porsche) to develop more affordable cars for working people. Known as Volkswagen (People's Car), this new automobile was intended to increase the number of German drivers.

When the war started, Volkswagen shifted its focus to producing military-grade vehicles for the German war effort.

As with Hugo Boss, a large proportion of Volkswagen employees were prisoners brought in from concentration camps. As a significant Nazi collaborator brand, Volkswagen also paid compensation to the surviving relatives of their former slaves.

4. Ford

This American car manufacturer has its fair share of guilt due to strong nazi connections. The founder Henry Ford was honored by Hitler's regime in 1938 for being one of his most loyal foreign supporters.

When warfare broke out, Ford continued to trade in Germany and supplied their armed forces with much-needed vehicles. To manufacture cars on a large scale, Ford factories in Germany recruited workers from Auschwitz.

It was not until early in the 21st Century that Ford was exposed as a powerful brand that collaborated with the Nazis. When America joined World War 2, Ford started profiting from both sides by supplying the Americans too. Hence, Ford's ugly ties to the Nazi dictatorship were masked somewhat.

5. IBM: A Complicit Nazi Collaborator Brand

IBM played a very functional role in carrying out the Holocaust. Today it is most famous for its software products, though, in World War 2, it was busy building machines for the Nazis. These computers helped them keep track of many aspects of their military campaign.

For example, with help from IBM, the Germans collected vast amounts of data on the ethnic origins of their citizens. This database helped the Germans quickly identify Jews and other minorities and organize their deportations.

This is one of the biggest American brands that collaborated with the Nazis ― the country's supposed enemies. The scale of the extermination, courtesy of their computers, clearly gave them no compunction.

6. Siemens

Siemens is a thriving technology company with a stain on its past. It was already an established name in Germany before anyone had heard of Hitler. But, as one of the major brands that collaborated with the Nazis, it benefited financially from the surge in demand for weapons. As profits increased, many regular employees were forced to serve in the army.

That left Jews, Gypsies, and others from concentration camps to pick up the workload. Siemens was responsible for setting up factories within the camps themselves.

Unfortunately, the world was reminded of the link between Siemens and the Holocaust when the company tried to secure a patent for the word "Zyklon" in 2001. This means cyclone in German but sounded similar to the Zyklon B chemical used by Nazis to execute victims in gas chambers

7. Kodak

Kodak was an American Nazi collaborator brand. By this stage of the list, its story will sound very familiar. The company operated throughout Europe in the 1930s. When America joined the allies in their fight, companies like Kodak were forbidden from exporting to enemy countries.

The greedy photography brand found a loophole to keep earning profits in Germany. By working through offices in neutral Portugal and Switzerland, the directors in America retained ties with Germany without breaking the law.

Kodak bought materials and equipment from Germany during the war and manufactured products in German factories with the use of prisoners.

8. Bayer: The Nazi Collaborator Brand That Made Zyklon B

To finish the list off, let's discuss the company directly involved in the killing of innocent people. Although its manufacture of essential medicines is a force for good nowadays, Bayer was once responsible for much darker deeds.

Bayer became an individual company after World War 2 but was a division of IG Farben during the Holocaust. IG Farben was the organization that produced the infamous Zyklon B used in Nazi gas chambers. This horrific weapon was introduced as a quick and efficient means of mass murder.

Ironically one of Bayer's greatest inventions, aspirin, is thought to have been invented by Arthur Eichengrün ― a Jewish chemist working for the company. The invention is often attributed to German Felix Hoffman instead, though some argue that Germany simply didn't want to give credit to Eichengrün because of his heritage.

So even today, questions about Bayer's role as a nazi collaborator brand and its overall legacy still linger.