The predominantly oral culture of the Norse society that Vikings came from means that they have primarily been depicted from the outside.
For this reason, the information available on their everyday life and culture is sparse and riddled with speculation.
For instance, did the Vikings share their wives?
There is no record of Vikings sharing their wives. If anything, the available evidence suggests that Viking men of high status often had several female partners apart from their wives.
This left low-ranking Viking men at a disadvantage when securing partners for themselves.
The remainder of this article will explore gender relations in Viking society, explain how many wives a Viking could have, and describe how the Viking men treated their wives.
Also see Did Vikings Name Their Ships? to learn more.
Could Vikings Have More Than One Wife?
Theoretically, Vikings could have more than one wife. Their pagan religion did not proscribe polygyny.
However, they usually did not take multiple wives because Norse laws laid down a number of conditions and stipulations governing the forming and dissolving of marriages.
Like most cultures of the time, Norse society too was male-dominated.
Norse men dominated public life and filled the ranks of leaders and warriors, while women were primarily relegated to household work and child-rearing.
As an extension of such privileges, Norsemen were allowed to have multiple sexual partners at the same time, while their women did not enjoy the same benefits.
This practice is known as polygyny.
However, Vikings usually did not take multiple wives due to several practical legal and financial considerations.
Gender norms in Norse society were far more equitable than in many other parts of the world at the same time. This distinction was most notable when it came to laws governing gender relations.
When it came to marriage, Norse society offered women protections and options that were unheard of elsewhere at the time.
Unlike their counterparts in most of Europe, women in Norse society had a say in the choice of mate their families selected for them.
Norse law also allowed women to initiate divorce proceedings if they were unhappy with the state of their marriage.
Laws also placed some financial obligations on any Viking looking to take or part from a wife.
A Viking had to be able to materially support any woman he married, as well as all her offspring.
Similarly, upon divorce, a Viking would be obliged to return the dowry his bride’s family had paid him on their marriage.
Thus, keeping multiple wives needed great financial resources.
Wives also had greater rights, including initiating divorce and collecting dowry at its conclusion.
So, in spite of there being no prescription of a Viking taking multiple wives in either law or religion, Vikings usually took only one wife.
Also see Which Country Has the Most Viking Heritage? to learn more.
How Many Wives Did Viking Men Have?
Viking men usually had only one wife. However, the wealthiest Vikings also often had multiple mistresses who resided in their homes along with their offspring.
While Vikings’ wives led the household, mistresses had limited rights, including the freedom to move out unless they were slaves.
Norse law effectively limited the number of wives Viking men could have without outright proscribing polygyny.
There were no such limitations when it came to simultaneously having multiple sexual partners.
The number of sexual partners a Viking could have at the same time was only limited by the extent of his resources.
Many high-status Vikings kept several mistresses.
However, it should be noted that, unless they were slaves, mistresses of Norsemen were not without rights.
Though not as high as that of wives, their status was higher than that of a concubine. Mistresses could choose to leave their household if they so wished.
Thus, while a Viking did not have the same obligations to a mistress as his wife, he still had to keep his mistresses happy.
Once again, this suggests significantly more equal gender relations in Norse society than was the norm elsewhere in Europe at the time.
In fact, some scholars speculate that the reason Vikings turned to raiding other civilizations was a lack of women for low-ranking men. 
As low-ranking Vikings did not have enough women they could marry, they had to find them elsewhere. This is also one source of the speculation that Viking men shared wives.
Also see Did the Vikings Have Ranks? to learn more.
How Did Vikings Treat Their Wives?
Vikings treated their wives relatively well by the standards of the time, as Norse women had significant protection under Norse laws of marriage.
The wives of Vikings had a say in their choice of mate and rights to initiate divorce proceedings if they were dissatisfied with marriage.
Vikings had to treat their wives relatively well by the standards of their time.
If they were unhappy in their marital homes, Norse women could initiate divorce proceedings. They could also reclaim the dowry that their families had paid at marriage.
For these reasons, Norse women enjoyed far greater status than women elsewhere at the time.
They could own property or conduct business and, as wives, held sway over domestic affairs.
Even mistresses enjoyed rights, including the freedom to break away from the man, as long as they were not slaves.
Norse women often traveled with Vikings on their voyages.
Mitochondrial DNA evidence has also concluded that they played a significant role in setting up and growing new Viking colonies in many parts of Northern Europe, including England and Iceland.
Some Norse women retained significant power as queens or seeresses.
Elaborate burial chambers full of luxurious goods and runestone inscriptions commemorating dead women have established these facts.
Finally, Icelandic sagas, the predominant literary artifacts left behind by the Vikings, testify to the strong role women played in Norse society.
Their portrayal of women as strong characters well equipped to argue with their men suggests a society where Vikings would have had to treat their women well or risk losing them.
Apart from the lack of contemporary first-person accounts, confusion about the nature of gender relations in Norse society also arises from the biases of later historians writing about Norse culture.
Often the morality of Victorian Christian historians is transferred to polytheistic Norsemen in these accounts.
Perhaps the obsession with multiple partners and stories about the Vikings sharing wives tell us more about the hopes and fears of Victorian England than they do about pagan Norse society.
Vikings did not share wives. The idea that they did is reflective of the moralizing speculation of later historians.
Also see Did the Vikings Fight the Mongols? to learn more.