They were the odd couple of the 18th century; one in his mid-60s with puffy grey wig perched on his head and uncontrollable Tourette’s tics and gestures, the other half his age and known to like a tipple and a frolic with a prostitute.

As if the friendship between Dr Samuel Johnson and James Boswell was not curious enough, their jaw-dropping decision to stride it out on a gruelling 83-day walking tour of the weather-beaten and untamed outer reaches of Scotland was bordering on insanity.

Johnston and Boswell set off less than 30 years after the 1745 Jacobite Rebellion, when whisky was still distilled illegally, roads were scarce and travel was by foot, bone-jangling carriage, horseback or over very turbulent seas in a rickety boat.

Their extraordinary journey to the Highlands and the Hebrides during an autumnal season of relentless rain and storms, took Johnson - plump, partially deaf and blind and who had rarely travelled outside of London - on a grand Scottish tour which led to two of the earliest travel books and paved the way for centuries of tourists who would also explore the nation’s wild islands and highland beauty.

While for the then 32-year-old Boswell there was a chance to witness Johnson up close for nearly three months, providing a wealth of material for his admired biography, Life of Samuel Johnson.

Now two new productions are set to bring modern audiences a flavour of the unlikely duo’s epic and often comedic journey from Edinburgh to Iona via Fife, Aberdeenshire, the Moray Coast and the Western Isles.

Later this year a Sky Arts documentary, Boswell and Johnson’s Scottish Road Trip, will track comedian Frank Skinner and best-selling novelist Denise Mina as they recreate the 1773 journey, travelling in the same 18th century style as Boswell and Johnson.

While next month’s 2020 Scottish International Storytelling Festival will feature a collaboration between writer Donald Smith and actors Andy Cannon and Christopher Craig which reconstructs parts of the epic journey.

According to Donald, Director of the Storytelling Centre, there are parallels between the pair’s 18th century escapade and modern life, both in the great escape from lockdown that has seen Scots rediscover the Highlands and islands and the modern debates surrounding Scotland’s relationship with its closest neighbour.

“Boswell was Scots to his roots and is very defensive about the Scots and Scottishness, while Johnson has this very English take on it all,” he says.

“There are two things that fuel the humour, Johnson is like this English bulldog and Boswell is like a Scottish terrier. Together they are a hoot.

“Boswell was a heavy drinker and Johnson was teetotal, which leads to all kinds of escapades. It’s like 18th century Laurel and Hardy.”

Boswell, born in Edinburgh in 1740, had toyed with the idea of becoming monk before spiralling into drink and a libertine lifestyle. He was 22 when, during a visit to London, he met Dr Johnson.

He quoted their first conversation in Life of Samuel Johnson, saying: “Mr Johnson, I do indeed come from Scotland, but I cannot help it”. To which Johnson replied: “That, Sir, I find, is what a great many of your countrymen cannot help.”

It set the scene for a friendship driven by verbal sparring, with Johnson’s deprecating remarks about Scots robustly foiled by Boswell’s defence of homeland.

Their travels hit a stuttering start in mid-August at Boyd’s Inn in Edinburgh, where the cleanliness dismayed Johnson. Boswell wrote: “He asked to have his lemonade made sweeter; upon which the waiter, with his greasy fingers, lifted a lump of sugar, and put it into it. The Doctor, in indignation, threw it out of the window”.

The pair then travelled up the east coast, stopping at St Andrews to indulge their interest in John Knox and Mary, Queen of Scots.

They then followed the coast towards Aberdeenshire. A bit like today’s NC500 tourists plotting their route, they plotted an anti-clockwise course along the Moray Coast to Inverness and then to the Western Isles.

At times their journey resembled a lengthy pub crawl as they noted the quality of the inns and the food.

In Montrose, Johnson noted: “At our inn we did not find a reception such as we thought proportionate to the commercial importance of the place; but Mr Boswell desired me to observe the innkeeper was an Englishman, and I then defended him as well as I could.”

Dundee, it was noted, was “dirty, despicable”. They even recorded their first taste of Arbroath smokies.

Having travelled through Glen Shiel, the pair arrived at the inn at Glenelg. Often praised today, Boswell and Johnson gave it the equivalent of a one-star TripAdvisor review. Having arrived “wearing and peevish”, they discovered “no meat, no milk, no bread, no eggs, no wine. We did not express much satisfaction.”

The Highland terrain posed even greater stress. Dangerous and often impassable except on foot, they were often in remote spots, miles from inns or shelter or ankle deep in a peat bog.

Nevertheless, they trudged on through stormy weather and with Johnson often suffering from colds, increasing deafness and seasickness on the journeys between the islands.

The trip from Coll to Skye was undertaken during a vicious storm, with Boswell fretting over whether the boat might sink or explode, and troubled that he couldn’t understand the sailors’ Gaelic.

Johnson was no great fan of the language, describing it as “the rude speech of a barbarous people, who had few thoughts to express, and were content, as they conceived grossly, to be grossly understood”.

But in Skye, they were delighted to meet Flora MacDonald, and slept in the same room that Bonnie Prince Charlie had slept in.

“Both were over the moon because they were besotted with the story,” he adds.

The pair told of finding the Highlands still occupied by military garrisons, cleared by immigration and spoke of the suppression of Highland culture and oppression of the clans.

The isle of Raasay turned out to be a favourite spot, where the pair enjoyed the clan chief’s hospitality and a raucous ceilidh, with Boswell dancing a jig on the flat summit of Dun Caan.

“There is a political edge and a cultural edge to what they wrote,” adds Donald.

“Both felt that in Raasay they had come close to authentic old Gaelic culture and way of life.”

By October 1773 they were in the Saracen Head Inn in Glasgow’s Gallowgate, revelling in a roaring coal fire and conversation with professors from Glasgow University.

The trip would come to a sorry end, however, at Boswell’s family’s Ayrshire home.

“Johnson and Boswell’s father had an enormous row; they were total opposites in religious and political beliefs,” adds Donald.

“Johnson was a kind of father figure to Boswell. He knew Boswell could be a bit out of hand, but he also knew he was a real literary talent.”

Johnson’s A Journey to the Western Islands of Scotland, was published 245 years ago this year, followed a exactly decade later by Boswell’s The Journal of a Tour to the Hebrides with Samuel Johnson.

Adds Donald: “Both wrote their own versions of their tour differently. They go to the same places but see things differently.

“Which shows how much about travelling comes down to the way the individual experiences it and sees it.”

Tour to the Hebrides is part of the Scottish International Storytelling Festival which runs from October 17 to 31. For details go to www.sisf.org.uk.