St. Ninian, a British bishop who lived in the early 5th century, is credited with the conversion of the Southern Picts of Scotland. The earliest known church built by St. Ninian was at Withorn, or the ‘shining place’. A poem written by a monk at Withorn in the late 8th century tells how Nynia was appointed to lead 'companies of people to the golden-glowing constellations in the starry sky'.

This cross design is formed by straight line knotwork (a symbol of eternal life) surrounded by a radiant circle (the sun symbol).