Their men became known as the 'blue men of the Sahara' because the dye from their distinctive indigo scarves rub off onto their faces giving them a mysterious air. The Tuareg evoke images of a long forgotten and romantic age.
But behind the ancient way of life is a culture so progressive it would even make some people in liberal western cultures blush. Women are allowed to have multiple sexual partners outside of marriage, keep all their property on divorce and are so revered by their sons-in-law that the young men wouldn't dare eat in the same room
Before a woman marries, she is free to take as many lovers as she wants.
'They turn a blind eye,' explained Butler. 'The young girls have the same great freedoms as the boys
For years, the men of the Tuareg have been able to ride to a young woman's tent, and sneak into the side entrance - while his well-trained camel stands quietly and waits.
However, there is also a code of practice which none would dare break. Privacy is all important for this centuries old tribe of nomads, who once crossed the desert bringing dates, salt and saffron south, and slaves and gold north.
The women also make poetry eulogising the men,' says Butler. 'There is high romance and idolatry.'
Many marriages end in divorce among the Tuareg. And when it happens, it is the wife who keeps both the animals and the tent. And it is she who normally decides that she’s had enough.
The mother's camp, Butler explains, is the root of the community, the home everyone returns to - and this arrangement ensures it stays that way.
And there is no shame in divorce. Families will often throw their daughters a divorce party, to let other men know they are available once more.
We were all sitting down to dinner, and the man has his back turned. She said the poor man was completely horrified because he has to eat with his mother-in-law.'