There are royals coming to Downton!

The new cinematic outing for Downton Abbey sees the servants and aristocrats of the famous house receive a visit from King George V and his wife Queen Mary, prompting much panic and excitement.

One of the most prominent royals featured in the film is that of Princess Mary, Countess of Harewood, portrayed by Peaky Blinders actress Kate Phillips.

The polite royal shares scenes with the Crawleys but we also see a look at her own personal issues.

But who was Princess Mary, Countess of Harewood in real life?

Here is all you need to know about the new arrival at Downton Abbey.

Downton Abbey: Who was Princess Mary, Countess of Harewood?

Kate Phillips in Downton Abbey (2019)

Princess Mary was the only daughter of King George V and his wife Queen Mary and was born on April 25, 1897 when her parents were Duke and Duchess of York.

Mary had to older brothers: the future kings Edward VIII and George VI, the latter being the father of our current Queen Elizabeth II.

There were also three younger siblings: Prince Henry, Duke of Gloucester; Prince George, Duke of Kent; and Prince John.

During World War One, Mary came out of her secluded royal life to launch a charity campaign in support of British troops and sailors, often visiting hospitals and welfare organisations alongside her mother.

The King Celebrates his birthday on Tuesday June 3rd 1902. This interesting photograph includes His Majesty, The Prince of Wales, Princess Mary, Countess of Harewood, The Duke of York and The Duke of Gloucester.

The Princess set up the Princess Mary's Christmas Gift Fund, giving up to £100,000 worth of gifts to British soldiers and sailors for Christmas, 1914.

She worked as a nurse at Great Ormond Street Hospital and also focused on the Girl Guide movement and Women's Services.

On February 28, 1922, Princess Mary married Viscount Lascelles, the heir of the Earl of Harewood. Mary was 24 and he was 39.

Reports indicated that Lascelles proposed to Mary after a wager at his club.

The royal wedding saw substantial media attention and attracted large crowds, being the first to be covered by fashion magazines such as vogue.

The Princess Mary, Princess Royal and Countess of Harewood visiting Gateshead 6 August 1937 The Countess greeting one of the tenants after opening the Church Army Homes at Temple Green, Bensham

One of Mary's bridemaids was her friend Lady Elizabeth Bowes-Lyon, the future Queen Elizabeth and eventual Queen Mother.

The marriage saw two sons: George and Gerald Lascelles.

The couple had homes at Chesterfield House in Westminster, Goldsborough Hall in Yorkshire, and Harwood House, the seat of the Lascelles, which became the couple's chief residence when Lord Lascelles became Earl of Harewood with his father's death, making Mary the Countess of Harewood in 1929.

Mary's father awarded her the title of Princess Royal in 1932 following the death of his aunt Princess Louise, Duchess of Fife.

There were ructions in the family when Mary's closest sibling Edward VIII abdicated the throne in 1936 to marry his lover Wallis Simpson and he became an outsider within the Royal Family for choosing love over duty.

King Edward VIII - Abdicated 10 December 1936 then became the Duke of Windsor The Duke of Windsor pictured with his sister Princess Mary, Princess Royal and Countess of Harewood 16 March 1953

Edward was made Duke of Windsor but lived abroad, where Mary visited her brother in Vienna with her husband.

The schism was exacerbated when Mary allegedly refused to attend the wedding of her niece Princess Elizabeth (later The Queen) to her husband Philip Mountbatten, in protest at the Duke of Windsor's lack of invite, but gave ill health as her reason for not attending.

The Princess Royal also visited the Duke of Windsor at the London Clinic following his eye surgery in March 1965, spending time with Wallis, Duchess of Windsor, in one of her few meetings with members of her husband's family.

Mary also visited troops, services, and welfare organisations throughout World War Two in various capacities.

The Princess Mary, Princess Royal and Countess of Harewood took the salute at a march past at Catterick Camp 18 May 1953 when the Royal Corps of Signals concluded its regimental weekend

Her husband died in 1947, but the Princess Royal remained at Harewood House with her eldest son and his family, having decorated and renovated the house into being a true home for herself and her family.

Mary attended the Queen's coronation in 1953, and also represented her at the independence celebrations of Trinidad and Tobago in 1962 and Zambia in 1964.

The largely uncontroversial Princess Royal died of a fatal heart attack on March 28, 1965, at the age of 67 whilst walking with her son on the grounds of Harewood House.

Mary had lived through six monarchs: great-grandmother Victoria, grandfather Edward VII, father George V, brother Edward VIII, brother George VI, and niece Elizabeth II.

The Princess is largely seen as a well-liked, private, and uncontroversial member of the Windsor family.

Her title of Princess Royal was later given to the Queen's only daughter, Princess Anne.

She is portrayed in Downton Abbey by Peaky Blinders actress Kate Phillips.

Downton Abbey is released in UK cinemas on September 13, 2019.