WHEN I was travelling around Scotland last summer while researching my book on Mary (or Marie if you live in France like me), I spoke to many guides at the numerous castles and palaces that I visited. The conversations usually went the same way with them firstly explaining the history of my personal heroine and then becoming more and more quiet as they realised I knew quite a lot about the subject. When I was asked to explain my fascination with a Scottish queen from nearly 500 years ago, the conversation would stop, and actually I have no idea why I am so captivated with one of the most controversial monarchs to have ruled these shores. I am English and have never lived in Scotland. I live in the south of France and have never lived in the north of that country where she grew up. I’m not that interested in royalty and nothing in my schooling gave a hint that I would find myself entranced by a story that continues to this day.

When Mary embroidered the prophetic words "en ma fin gît mon commencement" (in my end is my beginning) during her imprisonment in England, she could hardly have known that some five centuries later, a former BBC employee who loves football and was brought up in a Blackpool council estate, should have such an (unhealthy?) interest in her life.

I know when it started. Aged around 11, I was taken to the cinema by my teenage cousin to see the 1971 film of Mary’s life starring Vanessa Redgrave (as Mary) and Glenda Jackson (as Elizabeth I). I only went because my cousin had been stood up by a boy she'd just met, but I remember it as the moment this crazy obsession began.

The why is not so clear. I can’t say I was particularly engrossed in the story on that night, and while Vanessa Redgrave’s portrayal was excellent, she shared little physical similarity with the contemporary paintings of Mary – few of which appear to show her legendary beauty – so I wasn’t entranced by that either.

What I do know is that since then I have avidly collected as many books on her as I could afford, including some first editions. I then visited as many castles, palaces, chateaux as I could in Scotland, England and France, usually boring family members and friends. This included regular attempts to visit a Marie-related chateau in the Paris area, constantly forgetting that they always close on Tuesdays.

Over the past year I have revisited those places as research for my book, On The Trail Of Mary Queen Of Scots. And while in grand French chateaux such as Blois, Orleans and Amboise, Marie appears to have been just a footnote, a passing whisper in the wind whose memory has faded, here in Scotland, I have regularly felt her presence while walking around the ruins of the buildings in which her story unfolded. The daughter of James V and Mary of Guise, she was born on December 8, 1542 in the Royal Palace of Linlithgow and spent her infancy in Stirling Castle, where she would later soothe the fevered brow of her future husband Lord Darnley, and say goodbye to her 10-month-old baby son.

She spent three weeks at Inchmahome Priory before moving to Dumbarton Castle aged five, to be guarded by French soldiers until the treaty of marriage between her and the equally young Dauphin of France was signed some five months later. Within another month, she would leave the country of her birth, not to return for another 13 years.

Holyrood Palace in Edinburgh – where she lived on her return to Scotland from France between 1561-1567 – is an obvious place to explore and research her life, especially as the rooms that saw the shocking murder of her secretary Riccio and where Mary entertained her second husband, Lord Darnley, have been so lovingly and expertly restored.

Yet it’s the other places where I feel she still exists in whatever form you believe in. At Hermitage Castle in Roxburghshire, I stood in the bleak but spectacular surroundings and wondered how on earth anyone could manage to live in such an isolated spot, and marvelled at the arduous journey Mary made here from Jedburgh in 1566, to visit her future husband, James Hepburn, 4th Earl of Bothwell. I’d driven the 26 miles that morning, yet Mary rode there and back in a day.

Dunbar Castle is not open to the public, but its remains hold the dark secrets that were shared between Mary Stuart and the Earl of Bothwell in the weeks following the murder of the king of Scotland. Walking the small and alluring harbour, I watched as another stone crashed into the sea from the ruins of the place where Mary and Bothwell sealed their union and indeed their fate, whether this was a willing act on Mary’s part or not. Mary had been en route to Edinburgh when she was stopped by Bothwell and 800 of his men, who offered to escort her to Dunbar Castle for her protection. What took place there remains a subject of historical controversy. Although a whole industry has evolved around the so-called love story of Mary, Queen of Scots and the Earl of Bothwell, I believe this to be fantasy. Many believe that on the first evening at the castle, Bothwell raped the queen and so now controlled her, meaning she had to marry him as they had "consummated" their relationship.

Lochleven Castle – where she was incarcerated in June, 1567 following her defeat at Carberry Hill – is a forbidding place, and one can only imagine the sheer desperation she must have felt as she was rowed across the loch to her prison. During my visit, I stood in the courtyard and looked out to the loch and imagined the water lapping against the walls as it did 500 years ago. Today the levels have receded and there is a pleasant picnic area where once there was water. It was there that Mary heard about her son James being crowned as regent and wept as the hopelessness of her situation overwhelmed her.

When she finally regained her liberty, Mary is said to have spent her last night in Scotland before fleeing to England at Dundrennan Abbey (near Kirkcudbright). During my visit there, I listened as the knowledgeable guide – a man named Glyn – explained his own theory about this, which just about destroyed this accepted story and which meant a last-minute change to my book, suggesting that Mary probably didn't stay her final night in Scotland there but at a private house nearby.

It was during her exile at Bolton Castle in the north of England that two "trials" implemented by Queen Elizabeth took place, neither of which she was allowed to attend. It was here that the famous Casket Letters first came to prominence, which effectively sealed Mary's fate yet were later proved to be forgeries.

Bolton Castle was also the place where I had my most intimate encounter with the woman who has stayed with me longer than any modern-day relationship. I remain convinced to this day that I had a conversation with her as I sat on a stone bench in the gardens looking at the hills that separate England and a distant Scotland. It was mundane at best, relating the time it would take me to make the journey to Edinburgh compared to her tortuous travels. I’m absolutely certain that I sensed her presence next to me, even if I couldn’t see her.

At Fotheringhay in Northamptonshire, where she was tried and executed, I looked at nothing, because nothing exists. The place where Mary drew her last breath, spoke her last words and looked at her last image, is now a completely empty space. There is no castle, there are no signs or plaques and there seems to be no knowledge of the tumultuous events that took place there on the February 8, 1587. My imagination worked overtime as I tried to replace the scene of rolling countryside and a gentle swaying river with the fortress that surrounded the end of Mary Stuart’s life. A sadder place I haven’t visited or seen in recent years.

So many of the places I visited have stories of Mary’s ghost wandering the halls or ramparts, sometimes in the company of her mother, Mary of Guise. I certainly don’t doubt them, having often caught a fleeting glimpse of something unearthly as I’ve stood seemingly alone in the very space that she inhabited all those years ago.

In all those castles, palaces, gardens and chateaux that I visited, Mary’s (Marie’s) footsteps have left behind a trace of her, yet throughout her brief reign in Scotland, not a single building was commissioned by her or built for her except a small bath-house in the gardens of Holyrood Palace. So how do we keep her story alive in this modern age of fast internet, social media and immediate celebrity?

One of the answers, I suppose, is my book and the hundreds of others that have been written and will be written about her. The multi-million dollar film that is currently in production, which is said to star Saoirse Ronan as Mary and Margot Robbie as Elizabeth I – will bring her story to life when it's released later this year, but how accurate will that be? Virtually every big screen adaptation of the time she lived in has taken artistic licence with the story, but then even Friedrich Schiller’s famous play, Mary Stuart – which premiered in Germany in June 1800 and outlined a meeting between Mary and Elizabeth I – was a complete fantasy. The "Mary, Mary quite contrary" nursery rhyme was sung by children in the 19th century, yet scholars now believe it wasn’t about Mary Stuart at all, but the rather more infamous "Bloody Mary", Mary Tudor.

All of this helps to keep Mary’s life alive, but at what cost to the true story?

A visit to any of the castles, palaces or chateaux outlined above and in my book can give you a hint of the real Mary, but so little has remained the same and so much has changed. Holyrood Palace is vastly different to the one she saw in the 16th century. Kirk o' Field – where Darnley was murdered – is buried beneath the University in Edinburgh. Tutbury Castle in Staffordshire – where she was imprisoned after being moved from Bolton Castle – has virtually disappeared and Chatsworth House, Derbyshire is a completely different one to the grand mansion in which she was also incarcerated.

In Scotland, even the landscape is different. In Mary's day, the country was effectively treeless with many of the huge woods and forests appearing in later centuries. Carberry Hill, where she was abandoned by Bothwell as her depleted army faced the Lords in a stand-off that resulted in her inevitable capture, was completely bare of trees, yet is now surrounded by a wonderful forest. In her time there were lochs that criss-crossed the country, making travel a hazardous experience no matter what the conditions. Most of these lochs have now disappeared with the onset of modern development, and even Scotland's climate was much colder in the 16th century – a mini ice-age during which even the summers were a trial.

Mary divided opinion when she was alive and continues to do so in the present day. There are those who regard her as a "wanton whore" who abandoned her son, helped murder her second husband and tried to overthrow the Queen of England while she was imprisoned. I prefer to think of her as someone who was completely incapable of making a rational decision when it was required and relied too heavily on powerful men who didn’t always have her best interests at heart.

It’s my wish that Mary, and indeed other notable figures from our long and rich heritage, shouldn’t ever be forgotten, despite the inevitable onset of time. I have a vision of her sitting at her table on the night before her execution, writing farewell letters to those who still stood alongside her. She is wearing the now-familiar black and white dress and veil and the candle flickers gently as the breeze seeps through the badly-fitted window frames: woman who had finished with the world and the world had finished with her. Then again, "in my end is my beginning" ... and though her reign was fleeting and her footsteps were light, the trail of Mary Queen of Scots is well worth tracing.

Roy Calley's book, On The Trail Of Mary, Queen Of Scots, is published by Amberley, £20

MARY QUEEN OF SCOTS: A BRIEF HISTORY

By Sunday Herald staff writer

Born in 1542, Mary became Queen of Scotland aged six days old, when her father, King James V, died. In 1548, aged six, she was sent to France to become bride of the young French prince, Francis, in order to secure a Catholic alliance against England. They married in 1558; when he died two years later she returned to Scotland, then in the throes of the Reformation. In 1565 she married Henry, Lord Darnley who, in February 1567, died in mysterious circumstances when the Edinburgh house he was lodging in was blown up.

Mary very soon afterwards married James Hepburn, Earl of Bothwell, who had been acquitted of Darnley’s murder. Soon afterwards she was imprisoned in Leven Castle and forced to abdicate in favour of her infant son, James VI.

In May 1568 Mary escaped from Leven Castle, and attempted to restore her rights as queen at the Battle of Langside, but was defeated and fled to England, where she spent 19 years imprisoned in various castles. Found guilty of plotting against Elizabeth I, her cousin, she was beheaded in 1587 at Fotheringhay Castle. She was 44. After Elizabeth's death in 1603, her son became James I of England and VI of Scotland.