A vital piece of Norwegian history has come to light.

Archaeologists have dug up the lost shrine of Norway's iconic and "miraculous" saint and king, Olaf II Haraldson, who met martyrdom at the dawn of Christianity in the European country 1,000 years ago, the Daily Mail reported.

Researchers at the Norwegian Institute for Cultural Heritage Research (NIKU) have announced that they have uncovered the wooden foundations of St. Clement's church where Olaf's remains were believed to have been enshrined after his sainthood.

The discovery reportedly confirmed historical accounts of King Olaf who was proclaimed a saint after being slain in battle. Historians said his remains were buried at a church in the city of Trondheim.

Anna Petersén, the excavation's director, said what they uncovered "is a unique site in Norwegian history in terms of religion, culture and politics."

"Much of the Norwegian national identity has been established on the cult of sainthood surrounding St Olaf, and it was here where it all began," she explained.

Olaf ruled Norway in the early 11th century at a difficult time in his country's history when its people began giving up their old gods for Christianity after the kingdoms of the then divided Norway were unified.

Historical accounts said Olaf was driven into exile in Russia by his foes and was later slain in battle on his return from exile.

It is thought that his body was carried away and buried at Trondheim. A year after his burial, Olaf's coffin was said to have been dug up to reveal well-preserved remains, with the hair and finger nails still growing. This led to him being declared a saint, historians said.

They said the people of Trondheim witnessed a number of miracles attributed to Olaf's holiness.

Olaf, Norway's patron saint, has been immortalised in the country's coat of arms, where he represents the golden lion holding an axe.