The Germanic tribes that invaded Britain spoke Old English which was often called Anglo-Saxon. Words that derive from Old English are be, strong, and water. It might not surprise you but Old English did not sound alike to present day English. They didn't even look alike which would make it difficult for native English speakers to understand. It has many more germanic words and was rarely written down. The western dialect was the main literary version while Anglo-Saxon kingdoms spoke different dialects. Old English was used until 1100 AD.