The father of Beorhtnoð æthling of Kent ruled Mercia between what years ?
Beorhtnoð æthling of Kent:  His father was Burgred of Mercia; his mother, Æthelswith, and his brother, Beorhtweald Ealdorman of Kent. Burgred of Mercia: Burgred (also Burhred or Burghred) was an Anglo-Saxon king of Mercia from 852 to 874.
852 to 874