Medieval Christians conceived of religious identity as a changeable status akin to nationality.

Evidence

In mediaeval usage it was possible to become a Saracen or a Moor, just as later men were said to ‘turn Turk’. Saracen means a man who holds the same religion as Muhammad, that is, a Muslim. — Norman Daniel, Islam and the West, 106

Categorization

• DEFINE: Clarifies that ‘Saracen’/‘Moor’ denoted religious adherence, not ethnicity, and could be adopted by conversion.
• XREF: Connects to the reader’s interest in how religious identity was conceived as mutable vs. fixed in pre-modern societies (compare the grafting-as-metaphor essay on transformation).