Æthelstan
Æthelstan or Athelstan - Reign 924–927
When I first started to research who was "in charge" in Belchamp Walter before Conquest I was first confused with the 904 on the Millenium Village Sign. Nobody in the village could tell me what the date related. Domesday is not really much help as not only is it unclear who was "Lord" before 1066 as the land seemed to have been either given to Aubrey de Vere or it was confiscated from (possibly Malet) and then given to de Vere (who was William I's cousin - I have to check this but they were definitely related and came from the same region in Normandy).
In 904, Wikipedia is unclear who was "King of England" - England didn't really exist as a country at that time and was a collection of Anglo-Saxon regions including East Anglia, Essex, Kent, Sussex, Wessex and Mercia. The region that is now Wales was West of Offa' Dyke and the region above Mercia was Northumbria.
Edward the Elder (c.874 – 17 July 924) was King of the Anglo-Saxons from 899 until his death in 924.
Edmund I - 27 October 939 – 26 May 946