This article contains spoilers for Game of Thrones season eight, episodes three and four

Image copyright Getty Images

Game of Thrones actress Emilia Clarke has revealed who was responsible for the show's infamous coffee cup scene.

In one episode of the eighth season, eagle-eyed viewers spotted a coffee cup on the table in the great hall, as Mother of Dragons Daenerys Targaryen sat, more appropriately, with goblet in hand.

Now, Clarke has revealed her co-star Conleth Hill, who portrayed master of spies Lord Varys, admitted to being responsible for the error during a pre-awards show party in September.

"We had a party before the Emmys recently and Conleth, who plays Varys, who's sitting next to me in that scene, he pulls me aside and he's like, 'Emilia, I have got to tell you something, love. The coffee cup was mine'," Clarke recounted to US talk show host Jimmy Fallon.

"It was his! It was Conleth's coffee cup. He said so. He said ' I think it was, I am sorry, darling, I didn't want to say anything because it seemed the heat was very much on you.' I was like 'what? what!?'"

The cup was originally identified as being from Starbucks but later confirmed to be from a local coffee shop in Banbridge, Northern Ireland, where much of Game Of Thrones was filmed.

HBO has since removed the cup from re-runs of the fourth episode of the final season.

The show's producers admitted the error at the time in a humorous tweet posted after the broadcast.

The hazelnut latte of Winterfell is the most recent high-profile example of a modern item making its way to a different time and place, it is certainly not the first.

Gladiator's gas cylinder (2000)

Image copyright Getty Images

Ridley Scott's Roman epic - fronted by a vengeful, best actor-winning Russell Crowe - dominated awards season. But it has since also found blooper fame.

During a battle in the Colosseum, a horse-drawn chariot flips over onto its side, revealing a gas cylinder.

A quite remarkable technological feat given that the movie is set in 180AD and stainless steel gas cylinders weren't invented until the 1800s.

Braveheart's Ford Mondeo (1995)

Image copyright Getty Images

The sight of US actor Mel Gibson playing Scottish independence hero William Wallace raised more than a few eyebrows at the time of the film's release.

But that was not as surprising as the appearance of a Ford Mondeo in a horseback battle against English invaders.

Talk about horsepower...

Downton Abbey's plastic bottle (2014)

Producers of the period drama were left red-faced after a modern plastic bottle appeared in a promotional photo for a forthcoming series in 2014.

Image copyright @downtonabbey/PA Wire

Perched on a mantelpiece behind Hugh Bonneville and Laura Carmichael, the bottle was spotted by eagle-eyed fans when the image was posted on Instagram.

Plastic bottles were not in wide use in the UK until the 1960s - 36 years after the series of Downton took place.

Although later deleted from Instagram and the ITV press site, the internet never forgets, no matter what the year...

Indiana Jones' faulty geography (1981-2008)

Steven Spielberg might be the visionary behind some of the best-loved films of the last 40 years, but it seems he wouldn't be much help in a geography test.

His Indiana Jones series - starring Harrison Ford - includes glaring map reading errors.

Image copyright Getty Images

Its opening instalment, Raiders of the Lost Ark, set in 1936, sees a plane fly over a map that includes Thailand and Jordan.

But there's a problem. Thailand was called Siam until 1939, while Jordan was known as Transjordan until 1949.

And Spielberg's cartography did not improve before 2008's fourth instalment Kingdom of the Crystal Skull, which shows a plane flying over Belize in 1957, at which time it was still known as British Honduras.

Back to the Futuristic guitar (1985)

Image copyright Getty Images

The inclusion of an anachronism in Back to the Future - a film about time travel - feels as head-spinning as it does fitting.

Its opening instalment sees era-hopping 1980s teen Marty McFly, played by Michael J Fox, travel back to 1955, ultimately filling in on guitar at his parents' high school dance.

McFly shocks the crowd by playing power chords during a performance of Chuck Berry's Johnny B Goode. "I guess you guys aren't ready for that yet," he tells the bewildered teens. "But your kids are gonna love it."

Prophetic words, as the guitar McFly is using is an Gibson ES-345, which was not introduced until 1958.

Mad Men's Saturday Night Football (2010)

Image copyright Alamy

Famed for its historical accuracy, Matthew Wiener's long-running US advertising drama Mad Men did not quite manage to maintain a spotless record.

News anchor-turned-TV sleuth Brian Williams used his NBC blog to point out that its brooding lead Don Draper simply would not have been able to watch a night-time NFL game on TV in 1964.

That's because prime-time football didn't start until 1970.

Follow us on Facebook, or on Twitter @BBCNewsEnts. If you have a story suggestion email entertainment.news@bbc.co.uk.