Forgotten samples from 1957 dig are from the walls of St Columba's cell

The samples were uncovered in 1957 by archaeologist Professor Charles Thomas at a site folklore claimed the saint had built a hut where he wrote the Cathach, a manuscript of psalms.

Prof Thomas argued that the flakes of hazel charcoal proved the old stories to be true, but a lack of dating technology led others to dismiss his findings as speculation and scientifically unproven.

Despite being rebuffed, Prof Thomas saved the samples in matchboxes and filed them away in his garage in the hope that science would one day prove him right. 

Now radio carbon dating led to a breakthrough which proves the wooden flakes, unearthed in an excavation of a wattle and timber structure, are from the exact period Columba lived in the Inner Hebridean monastery.

The samples have only now come to light after Prof Thomas' archive was passed to Historic Environment Scotland and was shared with the University of Glasgow, which submitted them for carbon dating.

Results show the hut dated back to between 540 and 650. Columba died in 597.

Altogether, ten radiocarbon dates were returned from samples from Prof Thomas' excavations, all dating to the early medieval period (AD 500-1100).

Prof Thomas died last year but Dr Adrian Maldonado, from the University of Glasgow, described the dating as vindication of his foresight in storing the samples.

"Thomas always believed he and his team had uncovered Columba's original wooden hut but they could never prove it because the technology wasn't there," he said.

"So, for us, 60 years later, to be able to send the original samples off to the radiocarbon dating labs and have them come back showing, within the margin of error, as something which may have been built in the lifetime of St Columba, is very exciting.

"This is as close as any archaeologist has come to excavating a structure built during the time of St Columba and it is a great vindication of the archaeological instincts of Thomas and his team."

St Columba is widely revered as a key figure in western Christianity and took the religion to Scotland from Ireland, landing on Iona in the year 563.

In the Life of St Columba, written 100 years after his death by his successor Adomnan, Columba was described as often writing in his cell on a rocky hillock, called Torr an Aba or "the mound of the abbot".

When Prof Thomas excavated the site 60 years ago, the carbonised remains of wattle walls of a small hut were unearthed below layers of loose pebbles, suggesting the wooden structure had burned down and the area filled over. The site was later marked with a cross.

Professor Thomas Clancy, Celtic and Gaelic historian at the University of Glasgow, said: "The remains on top of Torr an Aba had been dismissed as from a much later date.

"Now we know they belonged to a structure which stood there in Columba's lifetime.

"More than that, the dates, and our new understanding of the turning of the site into a monument not long after its use, makes it pretty clear that this was St Columba's day or writing house."

The tiny island of Iona is regularly busy with tourists from around the world and visitor numbers are expected to grow with the confirmation.

Derek Alexander, head of archaeological services for the National Trust for Scotland, which maintains the island, said: "It's one of the highlights of coming to Scotland, it's a bit of an adventure and pilgrimage in its own right for tourists.

"That's what people have been doing all the way really since Columba.
"The tourists of today are pretty much like the visitors of 1,200 years ago, it hasn't changed that much, and the more we find out about it the more significance I think it has."

The findings are being presented in a keynote lecture for the 8th International Insular Art Conference at the University of Glasgow.