The chapel was (probably) built in the early 14th Century as a chantry chapel, though the squat tower is an early/mid 16th Century addition. The whole was restored in 1869, when the bellcote was added, and is now Grade I Listed.
Following Edward VI's abolition of chantry chapels in 1547, the building became a residential school, though it also remained in use as a chapel, which welcomed Huguenot refugees from France in the late 17th Century. It was still a grammar school in 1910 (though perhaps no longer a church school from that year), but became Barnstaple's museum from 1928 until 1989.