Candida Casa was the name given to the church established by St Ninian in Whithorn, Galloway, southern Scotland, in the mid fifth century AD.
In 397, St Ninian established the first Christian mission north of Hadrian's Wall here, while the Roman legions still occupied Britain.
The church site quickly grew to prominence in the early medieval period, becoming a cathedral and monastery, and remaining a centre for pilgrimage despite the unstable political situation in the region.
At Whithorn, many monks were trained who later went into the missionary field to become famous apostles of Ireland and Alba, even as far north as the Orkney and Shetland islands.
Bishop Healy identifies the site with the great seminary of Rosnat, "...and undoubtedly was one of the chief sources from which Irish monasticism was derived.