There are many widely held perceptions about Scandinavians, with quite a few rooted in truth and others very far from it. For example, they are not all blonde or blue-eyed, nor is every Norwegian, Dane, or Swede directly descended from Vikings. Speaking of Danes and Swedes, there is also the commonly held notion that these two nationalities hate each other. As it turns out, this one comprises both truth and fiction.
Centuries ago, there most certainly was hatred between the nations of Denmark and Sweden, as evidenced by the dozens of wars fought between them. But to say that Danes and Swedes hate each other today would be a gross overstatement despite the occasional war of words and disparaging remarks.
The current state of relations between Denmark and Sweden is at times nebulous, and at other times complex. It has been hundreds of years since the Danes and Swedes last took up arms against each other, and just about the only modern-day hostilities between them involve words, attitudes, and even volleys of tweets during an epic social media dust-up.
What do Norwegians think of Swedes and Danes? See Why Do Norwegians Hate Swedes and Danes? to learn more.
Do Danes and Swedes Hate Each Other (and Why)?
The simple truth of the matter is that despite hundreds of years of vying for regional supremacy with great loss of life on both sides, modern Danes and Swedes do not hate each other.
But this does not mean that they are all too chummy either. After all, for several centuries, these two nations wanted nothing more than to eradicate the other, and this level of animosity does not dissolve away completely. (Also see Do People Still Practice the Norse Religion Today?)
At their closest points, Denmark and Sweden are separated by a mere 12 kilometers (roughly 7 miles), and yet Danes and Swedes are culturally distinct and speak different languages. 
In fact, the only way they can communicate with each other is through the neutral language of English, and quite often, it is through this non-native tongue that their wars of words are waged.
The Danish View Toward Swedes
The relationship between Denmark and Sweden and their respective constituents is complex, difficult to define, and at times, marked by seemingly childish and petty behavior.
Ask the Danes how they feel about their neighbors to the northeast, and the Swedes would likely be described as being stiff, overly reserved, and downright unfriendly. Other widely accepted stereotypes of Swedes depict them as:
- Having greater wealth than their Scandinavian counterparts
- Displaying a standoffish or patronizing attitude toward others (particularly other Scandinavians)
- Being more in tune with modern amenities and technology 
Sweden has a fascinating culture. See Do Swedes Actually Like Surstromming? to learn more.
The Swedish View Toward Danes
The Swedes, on the other hand, if asked to describe the good people of Denmark, might depict the Danes as happy-go-lucky people who, for better or worse, wear their emotions on their sleeves.  Other Swedish characterizations of the Danish include:
- Danes live more for the here and now and hedonistic pleasures than living sensibly and pragmatically
- Simple things like coffee and pastries are exorbitantly expensive in Denmark
- Danes are behind the times in both their attitudes and everyday implements
Due to their proximity to continental Europe and their direct interactions throughout history with the French and Germans, Danish people are also often perceived as possessing a bit of an elitist attitude toward their fellow Scandinavians across the water in Sweden and Norway.
Denmark and Sweden go to War… on Twitter
Perhaps the current state of relations between the people of Denmark and their counterparts in Sweden is best epitomized by hostilities that erupted on social media between official government Twitter accounts managed by the Danish Foreign Ministry on one side and the Swedish Communications Unit on the other.
What began as a seemingly harmless comment regarding home décor devolved into a heated exchange of increasingly hostile tweets between the Danes and their Swedish counterparts:
- The Swedes mocked the diminutive geographical size of Denmark
- The Swedes further pointed out Denmark’s lack of notable features such as lakes and mountains, to which the Danes countered by pointing out the number of their beaches
- Both sides poked fun at the other’s language and accent
- Accusations of flag-copying were exchanged
- Denmark’s losing record in wars fought throughout its history was ridiculed
- Finally, the insults turned to national fertility rates 
Fortunately, cooler heads prevailed, and the hurling of insults came to an end. While probably done in good fun and certainly entertaining, this very public exchange of barbs and ribbing does validate the notion that the rivalry between the Danes and Swedes, while certainly not rising to the level of centuries past, does still exist.
Sometimes non-Scandinavians mix up countries in the region. See Is Denmark and the Netherlands the Same Country? to learn more.
Rivalry is in their Blood
For much of the Viking Age, the nations of Norway, Sweden, and Denmark, as they are known today, did not exist yet. Instead, Scandinavia was comprised of competing chieftains and warlords, some more prominent than others, who vied for land, power, and wealth.
The Vikings are often perceived as ultraviolent people whose ruthless ways terrorized all of Northern Europe during the Middle Ages. However, what is often overlooked is that in addition to their raids against foreign people in faraway places like the British Isles and France, the Vikings also waged war against each other. 
Denmark and Sweden Have a Bitter History
To say that Denmark and Sweden are historical rivals would be a vast understatement when looking at the number of conflicts between these two Scandinavian countries. In fact, as far as recorded history goes, no two countries have gone to war against each other more often than Denmark and Sweden.
Numbers vary according to scholarly interpretation, but by some accounts, the Danes and Swedes have gone to war an astonishing 30 times since the 15th century (this is near twice the number of hostilities between England and France). 
Their interconnected history binds them to one another in a way that no two other nations share. There were times when each sought to obliterate the other and forever erase them from the face of the earth.
There is no true animosity between these two former enemies today, which is a testament to the high standard of civility cultivated throughout Scandinavia in the modern era.
Also see Why Do Doors Open Outwards in Sweden? to learn more.
Denmark and Sweden were Once Unified
For a period stretching over a century (although not continuously), the kingdoms of Denmark, Sweden, and Norway, were once unified under a single ruler.
With the formation of the Kalmar Union in 1397, these three Scandinavian nations, along with their respective territories, were ruled by a common monarch, Queen Margrethe I of Denmark. 
In the early 16th-century, the union began to show signs of fraying. In 1520, the execution of 80 members of Swedish nobility (an event that came to be known as the “Stockholm Bloodbath”) under the direction of then-leader of the union Kristian II of Denmark set the stage for Sweden to break away from the Kalmar Union and set off on its own path of sovereign independence under Swedish ruler Gustav Vasa. 
The end of the Kalmar Union also marked the beginning of a tumultuous period that saw Denmark and Sweden engage in numerous bloody conflicts with the aim of achieving supremacy over the strategically important Baltic Sea region.
Danes and Swedes are the World’s Happiest People
After centuries of animosity and war, Denmark and Sweden have learned to co-exist peacefully. According to metrics that measure a population’s collective sense of happiness, they have also developed into thriving countries.
According to the 2019 iteration of the World Happiness Report, Denmark ranked as the second happiest nation in the world, and Sweden ranked a very respectable seventh in the world (in fact, all 5 Nordic countries ranked within the top ten). 
The study, prepared by the United Nations’ Sustainable Development Solutions Network, examines six factors that relate to a heightened state of contentment:
- Life expectancy
- Social support
Based on these life-affirming results, it is safe to presume that Danish and Swedish forebearers would look upon their progeny with great pride and perhaps even vindication.
Centuries ago, Danes and Swedes fought for regional supremacy. Today, they are friendly rivals, especially when it comes to getting in the last word.
Also see Scandinavian Flags: Similarities and Differences to learn more.