The Oaths of Strasbourg, sworn in 842, were a pivotal moment in the early medieval period, as Louis the German and Charles the Bald pledged allegiance to each other in their respective vernacular languages. This event is significant for its early documentation of Old French and Old High German, showcasing the linguistic diversity of the time. The oaths also represented a crucial step in the political fragmentation of the Carolingian Empire, setting the stage for the development of modern European states.

The Oaths of Strasbourg in 842 provide the earliest substantial textual evidence of Old French and Old High German, marking a significant transition from Latin to vernacular written records. This linguistic evolution signaled the birth of distinct national literary languages, laying the groundwork for future literary movements in Europe.