St Michael’s is believed to be of late 13th or early 14th century date, although the south transept, which is set at a marked angle from the rest of the church, may be earlier. The church was enlarged and partly rebuilt in the 15th or early 16th century. The body of the church was restored in 1856 and 1884, and the tower in 1908.

Much of the visible fabric of the church is granite (including the piers) or rubble, neither of which lends itself to the easy scoring of graffiti.  There are, however, many marks scratched into a limestone effigy that is believed to represent Lady Dinham. There is further graffiti on the rood screen and the parclose screen in the Lady Chapel.

On the lead of the tower roof there are shoe and hand outlines (not uncommon on tower roofs), names and initials. In the nave some of the pew bookrests also have graffiti, although most of this seems relatively modern.  

Ilsington, St Michael