By the Twelfth Century the church had been extended a little at both ends and the footprint of the current nave and chancel date from this time. The priest’s door to the east side of the chancel was also added during this extension.

The priests of Mathon are listed inside the church starting with 1284.

At the time of the dissolution of the monasteries in 1542 Henry VIII gave the church and lands to the Dean and Chapter of Westminster Abbey and these remain the patrons of the living of Mathon.