I am currently finding it difficult to find a good informative answer on this, with the whole terrorist circlejerk going on. I am wrote a paper on Islam recently and am now quite interested in the religion and want to hear information from all sides in order to properly understand it.
I know that they would tax Jews and Christians, but I haven't found out much about what they did with other religions.
Essentially, Christians and Jews would be subjected to the poll tax, the jizya, and were seen as dhimmi, second class subjects - the word literally means "pay tribute" or "utterly subdued" - but they would not be forced to convert.
Those who were not Christians or Jews had to convert or die. EDIT: This stricture applies to discussions in Arab Spain.
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