slain at the Battle of Harlaw in 1411

(Link) Standing near the north wall and towards the east end of the interior of the church is one of the most remarkable grave slabs you will find anywhere. Made from an oddly yellowish stone, one side of this carries an incredibly intricate and detailed carving of a knight. The knight depicted was Gilbert de Greenlaw, who died at the Battle of Harlaw, a little to the north of Inverurie, on 24 July 1411. The stone is his grave slab.
Two things are immediately odd about it. One is the freshness of the carving, the other that the carving of Greenlaw stops just above his knees. Both are explained by the slab being reused for a member of the Forbes family in 1592. This led to it being cut down in size, but it also led to the side of the stone showing the knight being protected from the elements, which over the following centuries would almost certainly have weathered it to invisibility.

(Link) Within the ruins is this extraordinary recycled gravestone, considered by Douglas Simpson to be the only authentic, contemporary memorial of the Battle of Harlow. Originally the slab commemorated at Knight, Gilbert de Greenlaw, who was slain at Harlow on 24 July 1411 and whose image, wearing highly detailed armour, is incised in the yellowish sandstone. The knight is cut off at the knees. This truncation probably occurred in 1592 when the stone was re-used by John Forbes of Ardmurdo whose memorial inscription in Latin runs round the margins of the reverse side of the stone.