It's a different kind of same-sex marriage.
Nobody knows how it started but in northern Tanzania, heterosexual women marry each other.
An article in Marie Claire talks about an empowering tradition called nyumba ntobhu (house of women) that members of the Kurya tribe follow. This practice allows women to marry each other so they can hold onto their property if they no longer have husbands. These marriages involve women living, cooking, working, and raising families together — sometimes even sleeping in the same bed together but without sex.
By Kurya tribal law, only men are allowed to inherit property, but under nyumba ntobhu, if a woman is widowed and has no sons or if her husband leaves her, she's allowed to marry a younger woman who then can take a male lover and give birth to heirs on behalf of the older woman.
Each Kurya tribe is made up of 12 main clans which are divided into subclans. If a woman is widowed, the remaining members of the woman's deceased husband's clan want his property to stay within their group and would rather the widow marry a woman than get remarried to a man from another clan.
Also, the tribal leaders believe that these same-sex marriages solve the problem of widows, as a widow can keep her property and doesn't become a burden to the tribe when she gets old. In addition, most men don't want to marry a woman who is past menopause and can't bear children.
In almost all Kurya marriages, whether to a man or to a woman, there's usually a bride price or a dowry, to the younger woman's family. Dowries average between 10 and 20 cows (one cow averages around 500,000 Tanzanian shillings, or about $230), and ten girls are usually married off to the highest male bidder.
In Kurya's polygamous, patriarchal culture, where the more cows you have the more wives you can buy, more younger Kurya woman are opting to marry another woman instead of a man.
Kurya reporter Dinna Maningo tells Marie Claire, "They realize the arrangement gives them more power and freedom. It combines all the benefits of a stable home with the ability to choose their own male sexual partners."
Marriages between straight women are a win-win as they also help to reduce things like domestic abuse, child marriages, and female genital mutilation. "Sadly, these problems are rife in our society," Maningo says. "Younger women are more aware these days, and they refuse to tolerate such treatment."
Not surprisingly, there's no shortage of men who want to have sex with women in all-female marriages, and since there are many to choose from, the younger women look for men who are kind and reliable, and who are willing to be the biological father of future children.
In the Kurya culture, the more children one has, the richer you are. There are occasional disputes regarding paternal rights but most men don't want to go against the tribal elders who support these same-sex marriages.
Domestic violence is very prevalent in Tanzania and all-female households are seen as the best defense against male violence. If men attempt to take property or hurt one of the members of the household, they're swiftly punished by the tribal elders as they have no rights over the household. All the power belongs to the women.
If only more of the rights that women in same-sex marriages have can be given to all the women, but that seems to be a long way off.