For centuries after that, all English nobility used Norman French and the commoners used English.
I am not a linguist but I think it is incorrect to say that the commoners spoke English. They spoke saxon (or somesuch). English is what emerged as the two languages merged after 1066. Before that you might call it "old English" but it was hardly the language we call English now.
Calling what was spoken back then, even after the merger means that the Julius Caesar spoke "Italian". (well, old Italian)