Medieval Europeans could not recognize polygamous unions as marriages at all

Evidence

It needs to be kept in mind that Latin Christians define the married relation as inherently indissoluble except by death. The word marriage could not accurately, therefore, be used of any other sexual relation; it could not, for example, be used of many relations defined as marriages by the laws of modern European States. This was not pedantry; mediaeval Europeans simply understood only indissoluble monogamy by the word ‘marriage’. On the other hand, it was well known that in Islam there was polygamy. Latins always found it difficult to call any polygynous relation marriage. — Norman Daniel, Islam and the West, 753

Categorization

• DEFINE: Clarifies that ‘marriage’ in medieval Latin usage was definitionally restricted to indissoluble monogamy, making it a semantic rather than moral objection to Islamic polygamy.