My first impression of Dunkeld’s Cathedral of St Columba was on a cold day in late November, with the setting sun lengthening the shadows and frost already breathing its silent spell on the well-mown grass.

Standing on the bank of the River Tay and surveying the Cathedral from the south, I assumed that the building had taken place in two stages:    the first part, now roofless, I imagined must have been abandoned and allowed to fall into ruin, and later, a much more habitable structure had been added as an extension.    Either that, or the congregation in the western half preferred singing hymns under the stars.

But this isn’t how it happened at all.

The tranquil riverside location was first enjoyed by a community of Culdees, who built a monastery here around 730 AD.  A hundred years later, Kenneth MacAlpin, traditionally recognised as the first King of Scotland but now…