Throughout the twelfth century the lordship of Somerton stayed in the Arsic family. They were wealthy local landholders and may have been responsible for the major building work on the church, where the lower part of the nave probably dates from the twelfth century and possibly some of the north aisle as well.
The Arsic family came to Somerton as part of the broader redistribution of Norman landholding after the Conquest. Manser Arsic had received the barony of Cogges, near modern Witney, and Somerton formed part of that holding. The family were substantial local landholders across Oxfordshire, not merely at Somerton. Throughout the twelfth century the lordship stayed in the Arsic line, and they may well have been responsible for the most significant building work on the church during that period: the lower part of the nave probably dates from the twelfth century, and possibly some of the north aisle as well. The round piers to the arches of the north aisle are transitional between Norman and Early English style — an architectural detail that places the work confidently in the late twelfth century. If so, these stones are the most tangible legacy the Arsics left in Somerton. The family’s name largely disappears from the village record after 1230, when Robert Arsic died without male heirs and the barony divided between his two daughters — an event that would shape Somerton’s history for the next three hundred years. In the church, however, something of their century remains: in the curve of those round piers, and in the proportions of the nave they helped to build.
— Somerton Village History Project archive