Wow, interesting Dorchadas. Thanks!
So, if
Æðelfrið started to fall out of use after the
Norman conquest, is it possible that the Normans imported the Adalfrid cognate to England? Like how
Hrodger was imported, replacing
Hroðgar, and how
Hrodebert replaced Hreodbeorht. Could the same process have brought Adalfrid to England, replacing
Æðelfrið and then derived
Alfred from Adalfrid in some cases later?