The practice of having more than one spouse at a time is called
Islam
Islam
Islam
ISLAM
Islam
Islam is the traditional religion of the region.
Preponderantly Islam.
The region of North Africa mainly practices Islam. Also, as a side note, Southern Africa (the region) mainly practices Christianity. Here's a link to a picture from Wikipedia's article on Religion in Africa: http://upload.wikimedia.org/wikipedia/commons/7/7f/Religion_distribution_Africa_crop.png
Almost all over the world.
north africa
Islam
Arabian penninsula, Saudi Arabia.