However, it's important to note that:
* Old English was not the only language spoken. There were also speakers of Old Norse (brought by Viking settlers), Brittonic languages (the ancestors of Welsh, Cornish, and Breton), and likely some Latin spoken by the clergy.
* French began to be introduced after the Norman Conquest of 1066, but it wouldn't become a dominant language for many generations.
So, while Old English was the most prevalent language in 1066, it was far from the only one spoken on the island.