What type of language was predominantly used in religious and legal matters in the Middle Ages?

The predominant use of Latin in religious and legal matters during the Middle Ages can be attributed to its status as the language of the Roman Catholic Church and scholarly institutions. Latin was the lingua franca among educated individuals and was utilized in church liturgy, theological writings, and legal documentation. This ensured that important religious texts and legal codes were accessible to those involved in ecclesiastical and governmental authority, thus solidifying Latin's role as the foundational language in these spheres.

In contrast, Old English was primarily used in everyday communication and literature among the Anglo-Saxon population but did not hold the same authoritative position in religious or legal contexts. French, while influential in England post-Norman Conquest, was more commonly spoken in royal courts and among the nobility, rather than in ecclesiastical or legal texts. Celtic languages, though spoken in various regions, were not the primary medium for official religious or legal documents during this period. Hence, Latin's unique role made it the language of choice for these crucial aspects of medieval life.