IT was written 700 years ago and many believe it is the Scottish declaration of independence and went on to inspire the American version more than 450 years later.

But experts now believe they have traced the source of the legend that the Declaration of Arbroath directly inspired the American Declaration of Independence and conclude the myth was actually inspired by a 1970s magazine.

The story about the influence of the 1320 Declaration of Arbroath influencing America’s founding fathers in drawing up their 1776 document is described as “one of Scottish history’s most enduring myths”.

It was even enshrined into American law. In 1988 Republican Senator Trent Lott successfully introduced a motion in Congress that the annual anniversary of the Declaration of Abroath, April 6, should become National Tartan Day in the US, a celebration of Scottish heritage in America.

Mr Lott suggested that “by honouring April 6, Americans will annually celebrate the true beginning of the quest for liberty and freedom – Arbroath and the declaration for liberty”.

He was referring to the belief the American Declaration of Independence was directly inspired by the Declaration of Arbroath, written by Scottish barons to Pope John XXII, asserting the ancient independence of the Kingdom of Scotland and denouncing English attempts to subjugate it.

But a number of scholars have since devoted extensive time to disproving this theory. Among them was American cultural geographer Professor Euan Hague, who examined the sources used by the compilers of the Declaration of Independence, as well as records of their personal libraries, and concluded “the Declaration of Arbroath is conspicuous only by its total absence”.

Now, Historic Environment Scotland [HES] researcher Dr Laura Harrison claims to have traced the source of the myth to a 1970s magazine. In an HES blog, she said yesterday: “We have a responsibility to inform our members and visitors about the past with the most accurate and up-to-date information we can.

“One way we approach this is via exploring myth-building, rather than just myth-busting. We identify where an inaccurate myth exists, but we explore how it came to be believed.

“One example of this is a supposed connection between the Declaration of Arbroath and the American Declaration of Independence.

“So where does the myth come from? It appears to be relatively new. The earliest mention I have found is from 1975, when it is mentioned in an American Scottish Clan Society’s members magazine.

“Since then it has been mentioned in a number of places on both sides of the Atlantic, from Westminster to an American late-night television show Late Late Show with Craig Ferguson.

“It’s in popular history books and in the Resolution for Tartan Day.” Ms Harrison said the myth “may come down to an issue of naming”.

She said: “From about 1800 until relatively recently the Declaration of Arbroath was often called the Scottish Declaration of Independence. Thus, the two perhaps became conflated in people’s minds. Of course, as with all myths, there is an element of truth.

“The Declaration of Arbroath was one of a number of medieval documents that helped contribute to ideas of proto-democracy. But we can safely say Thomas Jefferson did not have a picture of it hanging in his study as he drafted the Declaration of Independence.”

Applying what she calls “some quickfire myth-busting” to some other common historical myths and stories, Ms Harrison also targets whether a spider really did inspire Robert The Bruce to continue his fight for the Scottish crown. She claims the story was popularised – and possibly made up – by Sir Walter Scott in his Tales Of A Grandfather.

She also dismisses the idea there were mer-people between the Hebrides and the Mainland.

The Blue Men Of Minch were said to swim the stretch of water looking for sailors to drown, which helped explain the losses of life in dangerous stretches of water. Ms Harrison also questions whether the Picts painted themselves blue before going into battle.