Adwell's original parish church is believed to have been built late in the 12th century, although the earliest documentation of it is dated 1254. It had only a nave and chancel. The latter may have been enlarged in the 13th century, judging by its east window which was early Decorated Gothic. In the 14th century new windows were inserted in the nave and a new west door was added. In 1553 the building was recorded as having a bell-cot with two bells. All of the walls were repaired around 1800, but by the early 1860s the building was considered too weak to be restored.