After his victory at the Battle of Hastings in 1066, the new King William gave most of the lordship of Somerton to his half-brother, the turbulent Bishop Odo of Bayeux, who features in the Bayeux Tapestry — which Odo may indeed have commissioned.
In 1086, in the Domesday Book, he is recorded as sharing Somerton with Miles Crispin, the son-in-law of Robert d'Oilly, the Constable of Oxford Castle. The under-tenant of the whole lordship was Wadard, a close associate of Odo who also appears in the Bayeux Tapestry.
The Domesday entry records Somerton as Sumertone. The manor was assessed at nine hides of land, with enough capacity for nine plough teams. Within the lord's demesne were two ploughs and a single serf, while the wider village population consisted of seventeen villeins and nine bordars working seven additional ploughs. There was a mill rendering twenty shillings and four hundred eels, forty acres of meadow, and one hundred and fifty-six acres of pasture. The value of the manor had increased from nine pounds before the Conquest to twelve pounds by the time of the survey.
What appears at first glance to be a dry administrative record is, in fact, a detailed portrait of a working medieval community — its people, its land, and the rhythms of life that would shape Somerton for centuries to come.
There is no evidence for the origin of the castle at Somerton but it seems reasonable to speculate that it may go back at least to the early days after the Conquest — perhaps little more than a stockade, commanding the track leading across the river to North Aston and Deddington. The original church building on the current site is believed to have been erected within eight years of the Conquest, though the only surviving element of that structure is the blocked-up Norman door in the south wall. The date of the preaching cross on the north side of the church is also obscure, but it is clearly medieval. Such crosses often go back to Saxon times and were frequently built on pagan sites.
After Odo's disgrace and banishment in 1087, Somerton was granted to the Arsic family and became part of the Barony of Cogges, near modern Witney.
— Somerton Village History Project archive