12 stars you forgot appeared in Downton Abbey - including 3 Game of Thrones actors and a Marvel celeb!

Downton Abbey is arguably one of the most popular period dramas of all time. Known for its extravagant set, charming characters and stellar ensemble cast, the series became a cultural phenomenon when it first arrived on our screens in 2010.

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Many famous faces have graced the halls of the fictional Yorkshire country estate and with the show being almost 12 years old, you may have forgotten some of the stars who appeared in the much-loved drama. 

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Iain Glen

Best known for his portrayal of Ser Jorah Mormont in HBO's fantasy series, Game of Thrones, you might be surprised to remember that Iain Glen once walked the halls of Downton Abbey. 

Iain appeared in five episodes of the show's second series and the 2011 Christmas special as Sir Richard Carlisle, who was engaged to Mary Crawley for a short while. 

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Fans may remember that Mary decided to pursue Richard after learning of Matthew's engagement to Lavinia. A short while after Lavinia's death, Matthew encouraged Mary to break off the engagement to Richard and after the latter insulted Matthew's late fiancée, a fight broke out between them. 

The last we saw of Iain in the series was when he left the Abbey, broken-hearted after Mary ended their engagement. 

James Faulkner

 Another Game of Thrones star, James Faulkner did appear in the period drama for just four episodes in the fifth series. 

James played Lord Sinderby in the drama, father to Atticus Aldridge who married Lady Rose MacClare (Lily James), cousin to the Crawley family. 

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Lord Sinderby was almost exposed to have fathered an illegitimate child during afternoon tea with his family and the Crawley's before Rose intervened and kept his secret concealed. 

You might also recognise James for his role of the lecherous Uncle Geoffrey in Bridget Jones' Diary.

Penny Downie

Australian actress Penny Downie played Lady Sinderby in four episodes of the drama. An accomplished stage performer, Penny is an associate artist of the Royal Shakespeare Company and has starred in various productions of the poet's plays. 

Fans may remember that when Lord and Lady Sinderby arrived at Downton, they feared that they might face resentment in Yorkshire due to their Jewish faith and don't initially approve when their son becomes engaged to Lady Rose, who isn't Jewish.

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Rose Leslie

Rose Leslie is perhaps most famous for playing wildling Ygritte in Game of Thrones - I know what you're thinking…another GOT star? 

But before starring opposite her future husband, Kit Harington, as Jon Snow's his love interest, she appeared in Downton Abbey. 

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The actress played the role of Gwen Dawson in eight episodes, appearing in the whole of season one as well as one episode in the final series. 

When we first met Gwen she was a maid on the Crawley's estate but with big dreams to become a secretary. Sybil helps her realise those dreams when she helps her get a job with a businessman who visits Downton.

In series six, Gwen returns to the Yorkshire home after 11 years away, having married a gentleman. The family don't recognise her as she's risen in class and after John Barrow informs them of her past occupation, she tells them about Sybil's kindness towards her. 

Siobhan Finneran

The Stranger star Siobhan Finneran played Sarah O'Brien in the period drama, the bitter lady's maid to Cora Crawley. She appeared in Dowton Abbey from series one to three. 

Fans may recall the close friendship between Sarah and Thomas Barrow, which weakened after Sarah's nephew, Alfred, started working at the estate.

The last we saw of Sarah was when she sneaked away in the night to travel to India to be a lady's maid to Susan MacClare. In 1924, Mrs Hughes receives word that Sarah had been employed by the new Governor's wife in India.

MyAnna Buring

MyAnna Buring, who you may recognise from The Witcher and The Salisbury Poisonings also appeared in Downton Abbey as maid Edna Braithwaite. She appeared in four episodes during season four as well as a Christmas special. 

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Fans may remember that Edna tried to pursue Tom Branson following the death of his wife, Sybil, but ended up being fired instead after Mrs Hughes didn't approve of her inappropriate behaviour. One particularly awkward moment was when Edna entered Tom's room while he was changing and kissed him. 

Richard E. Grant

Hollywood actor Richard E. Grant played the role of art historian Simon Bricker for four episodes during the show's fifth season. 

During his time as a houseguest of the Crawley family, Simon flirted with Cora. In a later episode, Cora visits London and Simon takes her to an art museum before inviting her to dinner. Cora accepts, not knowing that her husband Robert had travelled to London to surprise her.

Viewers may remember when Simon illicitly entered Cora's room in his nightwear before being caught by Robert, who tackled him to the floor.

Charlie Cox

Charlie Cox, who is best known for playing Daredevil in the Marvel Cinematic Universe, appeared in Downton Abbey in the first-ever episode. 

The actor played the Duke of Crowborough, a friend of the Crawleys who was brought to Downton by a telegram from then-footman Thomas Barrow (Rob James-Collier) with the prospect of marrying Mary (Michelle Dockery) for the Grantham money. 

It soon became clear that Thomas and the Duke had shared a romantic relationship during a previous visit to the Crawleys in London. When the Duke changed his mind about the proposal, Thomas blackmailed him using the love letters he had received from him, bitter that his plans to be the Duke's footman after he married Mary had fallen through. 

The Duke managed to burn the letters and left Downton for good the next day. 

Paul Giamatti

Hollywood star Paul Giamatti, who viewers will recognise from the TV series Billions, made a cameo in the 2013 Christmas Special, playing Cora's brother Harold Levinson.

In the episode, Harold stays with the Crawley's in London for Rose's ball and despite being a self-professed playboy, finds himself drawn towards Lord Aysgarth's (James Fox) daughter, Madeleine Allsopp (Poppy Drayton). 

Theo James

While Theo James might be best known for his roles in the Divergent film trilogy as well as in Sanditon, he did appear in just one episode of Downton Abbey during its first series. 

In the show's third episode, Theo played Kemal Pamuk, a handsome Turkish diplomat who takes a shine to Mary upon his visit to Downton. 

Viewers may remember that after signalling Mary to leave the dining room during dinner, he kisses her passionately and asks to visit her room during the night. Mary is shocked and declines. 

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Later, Thomas makes a pass at Kemal, who rejects him and threatens to expose him unless he leads him up to Mary's room once everyone is in bed. 

Kemal enters Mary's room and forces himself on her. He tells her that if she screams or rings for help, she will be scandalised. The pair begin kissing before Kemal has a heart attack and dies in Mary's bed. 

In a state of panic, Mary goes to wake up Anna, who soon realises that Kemal's body is too heavy to carry back to his own room. She then wakes Cora who quickly agrees to help in order to save Mary from social ruin. But when the three of them carry Kemal into his room, they are met by Daisy who has woken up early to light the fires. 

The four women remain the only witnesses to the scandal as Thomas later finds Kemal dead in his room and calls a doctor. 

Rade Serbedzija

Croatian actor Rade Serbedzija played Prince Kuragin in six episodes of the show during season five. Before appearing in Downton, Rade featured in a wide range of Hollywood blockbusters, including Snatch and Mission Impossible 2. 

When the Prince is introduced to us during the fifth series, it's clear that he and Violet Crawley (Maggie Smith) once shared a romantic connection in the past. He arrives at Downton years later, having been separated from his wife for many years. 

The prince then approaches Violet, asking her to be his lover for his remaining years but she objects as he does not know the fate of his wife. Later, his wife is found and they reunite at Violet's house and she turns him away for good. 

Maria Doyle Kennedy

Maria Doyle Kennedy, one of Ireland's most prolific artists, played Vera Bates, the estranged wife of John Bates (Brendan Coyle) for three episodes in series two. She has since appeared in major shows such as Outlander and The Wheel of Time. 

Viewers may remember that when Vera discovers that John is due to inherit an attractive sum of money following his mother's death, she threatens to expose Mary's secret regarding Kemal Pamuk and also refuses to divorce him unless he gives her a large amount of money.

John then returns to his mother's house to live with Vera after she insists that he come back to her. Upon learning of her infidelity, he leaves and rekindles his romance with Anna. When she hears of this, Vera returns to Downton and threatens to expose Mary's secret. Mary then enlists the help of her fiancée Sir Richard Carlisle, who bribes Vera into keeping quiet. 

Later, Vera dies by suicide and frames John for her death out of revenge. John is then convicted and sentenced to death before the sentence is reduced to life imprisonment.