x1 reflects proto-English/Jute-Anglo-Saxon culture (non-Celtic peoples of Great Britain arriving and settling from near Germany approximately between A.D. 500 and A.D. 800, or cultural descendants/relatives thereof) in aspect x2
Should probably exclude the Norse and the Normans (hence the approximate dating given in the definition). In some literature these people are called (or eventually become) the English whereas the people living on the island before then, who were of Romano-Celtic stock, are called the British and become known as the Welsh, Scottish, Irish, Manx, etc. They spoke Old English.