Th Open University has recently published a great playlist about the history of English from the Anglo Saxons till the age of globalization. These are mainly ten minutes videos and are done with a huge professionalism. The videos sum up all what the English learners need to know about English.
This Youtube playlist can be used by teachers especially history and language teachers. They can share them with their students or watch them in classroom . This could be a group work inducive task, divide students into fair groups and give them some pre questions about the content of the videos at the end of which they need to provide anwsers.
As a little note here, Open University is a great website for teachers looking for educational resources. The site provides both video and textual materials. Head over to Open Learn and start exploring materials you might need in your lessons.
Here is the playlist of the videos about The history of English in 10 minutes