On the 100th anniversary of the sinking of the Titanic, a historian has published an essay that contains fresh speculation two of the ship’s most famous and fashionable passengers were gay.

James Gifford’s writing studies the lives of two passengers aboard Titanic. The ship set sail on 10 April 1912 and sunk four days later, 375 miles (600 kilometers) south of Newfoundland, Canada.

The essay can be read on OutHistory.org. It asserts that, while travelling companions Archibald Willingham Butt and Francis D Millet were not lovers, there is evidence that both were gay.

RMS Titanic, which sunk on its maiden voyage 100 years ago, has become something of a legend. Famously trumpeted at the time as ‘virtually unsinkable’, it was the height of luxury and class. It boasted features more in common with a hotel and was designed with the Ritz, rather than a ship, in mind.

It was over three quarters of the way into its journey from Southampton, England to New York when Titanic received warning from other ships of dangerous ice. However, it continued at full speed and hit an iceberg at 11:40pm ship’s time on 14 April 1912 - exactly 100 years ago tomorrow.

Having just 20 lifeboats, Titanic was entirely unprepared for the sinking. Even if they had been filled, only half of the passengers on board would have made it safety. In fact, many of the first lifeboats to leave Titanic were only half-full because so many passengers didn’t believe it could possibly be sinking.

There were 2,224 people on board. Only 710 were saved.

Now historian James Gifford claims that of the 1,514 people who died in the Titanic tragedy two prominent passengers, travelling companions Archibald Butt and Frank Millet, were potentially gay.

Archibald Butt, known as Archie, was an influential military aide to US presidents Theodore Roosevelt and William Howard Taft. He is described by Gifford as ‘camp’ and a ‘dandy’ who was always impeccably dressed.

In the essay Gifford says: ‘The Washington newspapers seemed to have enjoyed guessing what female Butt would settle down with, ears attentive to any possible romantic connection.’

This, however, doesn’t satisfy Gifford, who was fascinated by Butt’s lifelong single status. He suggests that Butt, whose name was often attached to a number of different women in newspapers, gained his reputation as a ladies man from his gallantry, rather than anything sexual. He states that Butt ‘never took women as romantic partners very seriously’.

Gifford continues: ‘Most accounts referred to him as a lifelong bachelor. A handsome man who stayed in shape, Butt’s not marrying was a sticking point for me.

‘Of course there is no conclusive evidence that Archibald Butt was gay, and I find it highly unlikely, given Archie’s careful self-image control, that he ever committed to paper any overt thoughts of such a nature. He was too canny an individual for that, too conscious of the risk in military and political ranks, where such an idea would have put a quick end to any hopes of advancement.

‘So I can only suggest that my research results in an “impression” that he was homosexual. What struck me when I presented this idea to members of the Titanic Historical Society was that they all seemed to feel that the very idea of his possible homosexuality cast aspersion on Archie, that it dishonored him.

‘Of course men can like antiques, be mother-obsessed, remain an inveterate bachelor, notice the colors of ladies' dresses, live constantly in a home full of men, without being gay. We all know that, yes. But my gaydar was telling me something else.’

While Gifford’s findings on Butt are inconclusive, when it comes to Francis Millet, knows as Frank, he turns up far more convincing evidence.

Millet is known to have an affair with writer Charles Warren Stoddard in Venice in 1875. Stoddard would later leave him, devastating Millet.

Gifford even says that before researching Butt: ‘So far as I knew, Millet was the only gay man to die on the Titanic.’

In fact, he notes: ‘It wasn’t until further research indicated that he was travelling with Archie Butt that I started wondering about their relationship. As well as Archie's sexuality.’

Though they stayed separately on Titanic, they often shared a room on land.

While Gifford stops short of suggesting Butt and Millet were lovers, he points to sources that are more convinced of the pairing.

He says: ‘Writer Richard Davenport-Hines, in a March 2012 article for The Daily, refers to Butt and Millet (without citing sources) as lovers, but his simultaneously published book, Voyagers of the Titanic makes no similar claim.’

Gifford also quotes a newspaper piece written after their death that says: ‘The two men shared a sympathy of mind which was most unusual. None could help admiring either man.’

However, he concludes that: ‘Evidence about their friendship continues to remain elusive. To this day, I could find nothing concrete about this relationship.’

OutHistory founder Jonathan Ned Katz told the Huffington Post that while Gifford found no concrete evidence that Butt and Millet were lovers ‘he did end up thinking that when all of the aspects of Butt's personality were put together, it suggested to him that he may have been a repressed homosexual’.