Final answer:
The 'History of the Kings of Britain' was written in Latin, the language of the educated elite across Europe during the medieval period, despite the cultural shifts brought about by the Anglo-Saxon settlement and the Norman Conquest.
Step-by-step explanation:
The History of the Kings of Britain was written in Latin. This historic piece was crafted during a time when Latin was known as the language of the educated elite across Europe. Although the spoken Latin language had largely vanished by the eighth century, it remained the written medium of communication for the educated, including the clergy and scholars.
Following the departure of the Romans from Britain around 400 CE, various Germanic tribes including the Angles and the Saxons, known collectively as Anglo-Saxons, invaded and settled in England. Despite this societal transformation, Latin persisted as a scholarly language, even as Old English emerged as the vernacular language of the Anglo-Saxons after the Norman Conquest. It highlights the significant cultural and linguistic changes that occurred in the island nation throughout its early medieval history.