A marriage negotiation between royal houses triggered Portugal’s Muslim expulsion.

Evidence

Such dynastic details might seem totally irrelevant to the history of Spain’s Muslims, but in fact we need to pay close attention to them because out of the negotiations leading up to a marriage settlement between Manuel and Isabel there emerged, rather unexpectedly, the decision to expel Portugal’s Muslims. — L. P. Harvey, Muslims in Spain, 1500 to 1614, 109

Categorization

• SEED: Angle: how seemingly inconsequential dynastic marriage politics became the mechanism for a religious expulsion — the contingency of major historical events on personal details like a widowed bride’s grief.