 This was a time of building or extending churches with most parish churches in the island being built/rebuilt in a Norman style chosen by the abbey or priory to which each church had been granted.St Mary and St Martin being given to Cerisy Abbey.The islands remained part of the Duchy of Normandy until 1204, when King Philip II Augustus of France conquered the duchy from King John of England; thanks to Pierre de Préaux who decided to support King John, the islands remained in the personal possession of the English king and were described as being a Peculiar of the Crown.