IT has lain exposed to the worst of Scotland’s weather for 50 years since being moved to make way for an airport.

Now archaeologists have revealed how an old stone thought to have links to the Knights Templar is actually a medieval grave marker which may have connections to ancient nobles.

Digital imaging carried out on a weather-worn slab at Inchinnan Parish Church in Renfrewshire has revealed it to be hundreds of years older than previously thought.

Carvings now invisible to the naked eye were picked up by archaeological experts who believe the artefact was created around 1300 years ago.

Similarities in the markings suggest strong links with Govan in Glasgow, which was a site of power in the early medieval period.

Tracing on the Inchinnan relic resembles that of the Govan Stones, spectacular gravestones, massive curved hogback stones and a decorated sarcophagus which date back to between the 9th and 11th centuries.

The grave marker was part of a group of items relocated from the site of All Hallows, a small hill by the Black Cart Water.

The church there, thought to be the burial place of Saint Conval in the 6th century, was demolished in the 1960s for the creation of a Glasgow Airport runway, with material salvaged for the new kirk at nearby Inchinnan village.

This includes a group of 10 large stones known by locals as “Templar Stones”, so-called because the All Hallows church had been owned by the Christian military order, as well as three older slabs.

While the more ancient items were placed under cover, the “Templar Stones” were positioned outside, facing up into the Renfrewshire rain. But church leaders did not know that one of these was in fact hundreds of years older until locals from the Inchinnan Historical Interest Group investigated.

They called in Edinburgh-based Spectrum Heritage to scan the burial stones, with Glasgow University PhD student Megan Kasten making the Govan link.

While its exact origins remain unknown, the newly found carvings date it back to a period when All Hallows, as well as Govan and nearby Dumbarton, were burial places for the nobles of the kingdom of Strathclyde.

Kasten told The National: “Any discovery in the early medieval period contributes to our knowledge of the local area. You have the stones at Govan, which are similar – obviously there is a connection between the two sites, whether that is the sculptors, or church connections, or more about places of authority. It is unclear what is going on but this makes the ties to Govan clearer.”

Inchinnan HIG says the item “probably commemorated an important person within the kingdom of Strathclyde”.

Member Bill McCallum added: “People drive by and walk by all the time, but they don’t understand what’s around them. There’s a lot of history here. If someone merited a grave cover of this stature, they must have been of some standing.

“Dumbarton is four or five miles away from Inchinnan. There is nothing to say that someone of fairly high status in the royal family was not buried here.”

Symbols on the stone include a cross and faint panels of interlace. It also bears initials that were added at a later date, when it is thought to have been reused to cover another grave.

The discovery comes at the close of a season of work at All Hallows led by Inchinnan HIG and Calluna Archaeology, including geophysics and excavations. The company’s Dr Heather James said: “It has been great seeing the community and professionals working together to discover so much more about our fascinating heritage.”