View source for Companionate Marriage

Part of the process of equalizing the partners in a marriage said to have started in the late seventeenth, early eighteenth centuries. Preachers of the early seventeenth century preached about more companionship in marriage and hence triggered a movement in which partners put emotional satisfaction over increasing income and/or social stability. Values such as friendship, conversation, companionship, love, and sex became more important in a marriage than the 'old' values of money, social status, etc. This progress also brought up endearments and nicknames in a relationship. 

Also the honeymoon as we know it today, developed around that time. Before that the couple was bound to rather public traditions and rituals after the wedding. Even if they were granted some time alone (usually four weeks after the wedding), they were never really alone but surrounded by friends and family most of the time. With the development of companionate marriage, however, the concept of privacy was now more applied to them. Newly-wed couples also tended to travel around for some time. Here they had more privacy for them, although some sources say that especially the newly-wed women were often accompanied by more experienced women from their family (such as older sisters, aunts, etc.) to help them with new physical and psychological situations. 

Besides the rising of emotional expectation in the relationship, in the early nineteenth century there was also a feminist movement. Feminists declared that in a companionate marriage there had to be a reassessment of power relations between the sexes. That included earning and owning their own money, the right to vote, the right to represent themselves (instead of being represented by their husbands), and to take part in the political process. 

The education of women (especially in the upper class) also influenced the companionate marriage. The aim was that the women were on the one side able to educate their children on their own (even if that was still taken over by governesses etc.) and on the other side to spend their leisure time with something useful. For the first aim, John Locke suggested that the women learned to "read English perfectly, to understand ordinary Latin and arithmetic, with some general knowledge of chronology and history" (Stone 229). However, other voices said that women were such gentle creatures, that it would be more fitting for them to learn French (since it is such a gentle language), learn to dance and make music, and also crafting (needlework, embroidery, etc.). 


So, besides a shift in the values that mattered for a marriage also the wife as a person increased in importance and was not seen anymore only as a necessary accessory for getting an heir or having a woman at his side.
However, today companionate marriage has a different meaning. It describes a marriage in which both partners agree not to have children and in case of a mutual divorce, neither is responsible for the financial welfare of the other.


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Sources: 

Stone, Lawrence. ''The Family, Sex and Marriage in England, 1500-1800''. New York: Harper's Torch Books, 1979
 
Lamanna, Mary Ann et al. ''Marriages: Making Choices in a Diverse Society''. [http://books.google.de/books?id=heu0KLoVVnMC&pg=PA175&dq=companionate+marriage&hl=de&sa=X&ei=y7iUUompLcrYtAa4gIGQBA&ved=0CFcQ6AEwBA#v=onepage&q=companionate%20marriage&f=fal Link]