The Anglo Saxons - Ulwin/Unwin
The quest to confirm the 904 date (possibly 940AD or even 94AD) - There are multiple references to Ulwin/Unwin also known as Wulfwine as being the ruler of the region pre-Conquest. (I need to add links to my references here)
Many accounts of local history make reference to Doomsday, but that in itself is not really helpful. I think that a quote frpm F.W.Maitland is to the point: The "Domesday Book appears to me, not indeed as the known, but as the knowable.", the language used and the interpretations are key.
The Manor of Earls Colne. It is interesting that the history of the Belchamp Walter region is tied to Earls of Oxford. - Aubrey de Vere I, II and III (who was the 1st Earl of Oxford, appointed by Henry II)
A quote from the Wikip page:
In the time of Edward the Confessor Earls Colne belonged to a Saxon noble named Wulfwine also recorded as Ulwin/Ulwine. Ulwin's whole estate was given to Aubrey de Vere by William the Conqueror. His grandson Aubrey de Vere III became the first Earl of Oxford in the mid-twelfth century.
Castle Camps - another reference to Aubrey de Vere (Earl of Oxford)
William the Conqueror confiscated this land in 1068 (as with all English owned land) and gave it to Aubrey de Vere I. Aubrey had married the Conquerors half sister Beatrice, and been part of the 1066 takeover. His grandson, also Aubrey de Vere III, was created first Earl of Oxford by Henry II and built the castle. (Castls Camps and/or Castle Hedingham?
The de Vere family name seems to be synonymous with the Earls of Oxford. It spans 20 Earls over 600 years. The gene.com page for the Unknown father of Aubrey de Vere has an interesting quote:
The main joke in the popular television series To The Manor Born was that a Polish-Czech migrant, Bedrich Polouvicki, pretentiously changes his name to Richard de Vere.
This seems to stem from the fact that the father of Aubrey de Vere is not known and the de Vere name lasted for a long time.
Colne Priory at Earls Colne, Essex was a Benedictine priory, initially a dependent cell of Abingdon Abbey, Berkshire (now in Oxfordshire). It was founded by Aubrey de Vere I and his wife Beatrice in or before 1111.
Clergy for Belchamp Walter were sent from the priory Jon. Clark, and Richard de Oakham 1370.
Ulwin - Wulfwine
There are many references to Ulwin/Wulfwine in many accounts of pre-conquest times.
The Prosopography of Anglo-Saxon England (PASE) mentions Belchamp Walter in the account of land "transferred" from Anglo-Saxon to Norman ownership.