Built into the eastern end of the exterior S nave wall is an arch decorated with sawtooth. No early record of where this comes from has been found, but MacGibbon and Ross (1897) state that it formed part of the S doorway of the nave, which was later blocked up when a new doorway just E of it was built. The exterior base of the eastern wall, which comes from the medieval church, survives, but other parts of the church have been changed at various times, particularly during the later-18th century.The present parish church of Forgandenny appears first to have been built as a plain rectangle in plan. Later, a south extension was added and a north extension (taken down but known through excavations). Still later, a porch was built onto the west end. A major restoration took place in 1902-3. A more modern, heraldic memorial plaque has been inserted into the S exterior of the church, just below the medieval sawtooth arch. This refers to the Oliphant of Condie family.

Forgandenny was known formerly as Forground. The first known document to mention the church occurs in 1247, by which time it was already a mensal church of the bishopric of Dunkeld. In Bagimond’s Roll of 1275, the church appears as a vicarage, but by 1381 the vicarage appears to have become a prebend of a new canonry of Dunkeld Cathedral. At a date before 1378, an endowed chaplaincy had been established in Forgandenny’s church, which seems to have had an altar dedicated to St Mary. Then, in 1494 another endowed chaplaincy was established in the church, with an altar dedicated to St Catherine.

It has been proposed that the sawtooth arch should date from the early part of the 12th century (e.g. Fawcett, et al.), but the present author suggests that this form of deeply-cut sawtooth does not occur in Scotland before the second half of the 12th century. Fawcett, et al., do recognise that the base course of the east end wall may be part of a late-12th or early-13th century build. Gifford states that the early base of the east wall and walling above it are consistent with the 12th century. A comparison can be made within Scotland with the re-used arch at Lundie in Angus and a voussoir from Wheel in the Scottish Borders (now in the museum at Wilton Lodge, Hawick), though the Forgandenny arch remains unusual in that it has a second row of sawtooth pointing outwards along the upper edge of the arch.

In the 1792 Statistical Account of Scotland, it is stated: “The church, from a date upon the aisle, is supposed to have been built about 400 years ago.” As the two side extensions (transepts? chapels?) were added to an earlier church, did they originate as a result of the church becoming a prebend or to there being two endowed chaplaincies? MacGibbon and Ross wrote that the N extension was built as a laird’s seat for the Elephants of Condie after the Reformation, but that this was done away with when the Oliphants were given the porch, “which they converted into a burial vault, enlarging it at the same time, and making their seat over it, with an opening into the church”. They state further that, “The Ruthven vault, situated further east, is probably a structure of the sixteenth or seventeenth century.”