Much doubt has been cast over the veracity of the tale which was popularised by 19th Century storytellers keen to delight with tales of afar. Gloag’s odyssey to North Africa also became well embedded in local Perthshire tradition.
But, amid the suspicions, there are also accounts of those who remember Gloag, who was raised at Mill of Steps, Muthill near Crieff, and her family.
Some recalled playing cards and games with the “good looking woman” while others remember her mother’s nephew, Duncan McGregor, a local hero of the ‘45 rebellion, who often boasted of the Empress in the family.
Gloag left the family cottage in 1769 aged 19 after becoming increasingly at odds with her stepmother. Her own mother, Ann Key, died when she was just a small child.
Determined to emigrate to the Americas, Gloag reportedly set sail from Greenock - some say London - in May of that year but the ship was intercepted in the Atlantic by Barbary pirates from Salle in Morocco around two weeks into the journey.
Along with fellow passengers and crew, Gloag was seemingly sold at a slave market in Algiers and then presented to the harem of Sultan Sidi Muhammed XVIII.
After the Emperor, a moderate who did much to open up trade with Europe, fell for her natural beauty, she became his fourth wife and was given the title Empress after bearing him two sons.
Her departure from Scotland coincided with a campaign of piracy waged by North African pirates during the 17th and 18th Century.
According to accounts, the corsairs moved up and down the British coastline, usually hovering around the Bristol Channel, waiting to intercept passing vessels.
Raids as far north as Scotland were not uncommon with an earlier BBC Timewatch investigation claiming that 1.25 million white Europeans were captured by North African pirates and slave traders during this period.
Gloag, it has been suggested, was one of them.
After embedding in the Moroccan court, Gloag’s brother, Robert, a seaman, then began trading with Morocco, bringing gifts back to Scotland for her family and neighbours including farmer John Bayne who is referenced as a former lover of Gloag in some accounts.
Gloag, who some credit with aiding the sultan’s campaign to reduce piracy out of Morocco, was involved in the succession crisis after the death of her husband around 1790.
Gloag and her two sons were deposed and given sanctuary in a monastery, according to accounts.
The date and place of Gloag’s death remains unknown with the Perthshire country girl vanishing from records altogether.
The Biographical Dictionary of Scottish Women states there is no documentary evidence that Gloag made it to Morocco at all.
It said: “Sidi Muhammed did have white wives and concubines, but Dr Lempriere, who visited Sidi’s harem in 1789, saw no sign of a Scottish sultana.
“Perhaps Helen Gloag invented her own Perthshire legend to cover up some less savoury career in the Mediterranean, yielding the fine china - not a Moroccan product - which she apparently sent home.”
Jim Hewitson, in his book The Skull and Saltire, Stories of Scottish Piracy Ancient and Modern, said: “One fascinating sideline noted by present-day visitors to Sallee, the twin city of Rabat, is that there are numerous red haired, freckle-faced residents of the port. The tradition is that far-travelled Arab traders or slavers intermarried with the tribes of Ireland and some timein the early Middle Ages but perhaps Helen’s evidence is also evident.”
The Perthshire Advertiser set out its stall on the legend of Helen Gloag in 1839.
It reported: “We have reason to believe that this romantic story is, in its essential features, strictly true.”