Mary, Princess Royal and Countess of Harewood

The 1914 Christmas gift box.

During World War I, Princess Mary visited hospitals and welfare organizations with her mother;[5] assisting with projects to give comfort to British servicemen and assistance to their families. One of these projects was Princess Mary's Christmas Gift Fund, through which £100,000 worth of gifts was sent to all British soldiers and sailors for Christmas, 1914.[5][6] The 2017 value of that investment was £11-million.[7] She took an active role in promoting the Girl Guide movement, the VADs, and the Land Girls. In June 1918, following an announcement in The Gentlewoman, she began a nursing course at Great Ormond Street Hospital, working two days a week in the Alexandra Ward.[8][5]

The Princess (right) with her mother Queen Mary during the First World War

Princess Mary's public duties reflected her concerns with nursing, the Girl Guide movement, and the Women's Services. In the period leading up to her marriage, girls and women in the British Empire called Mary and its variants (including Marie, May and Miriam) banded together to form "The Marys of the Empire," and donated money toward a wedding present.[9][10] She presented this fund to the Girl Guides Association for the purchase of Foxlease, and following the exhibition of her wedding presents, she also contributed half the proceeds to the same cause, for upkeep, a total of £10,000, which enabled the project to go ahead.[11][12]

She became honorary president of the British Girl Guide Association in 1920, a position she held until her death. It was reported in July 2013 that British Pathé had discovered newsreel film from 1927 in which the ancestors of Catherine Middleton are, as Lord Mayors of Leeds, playing host to Princess Mary at the Young Women's Christian Association in Hunslet, Leeds; both Sir Charles Lupton and his brother Hugh Lupton, were the uncles of Olive Middleton – the Duchess's great grandmother.[13][14] In 1921, the Princess became the first patron of the Not Forgotten Association, a position she held until her death in 1965. The charity's first Christmas Tea Party was organised by Mary and held at St James's Palace in 1921 when she invited 600 wounded servicemen for afternoon tea and the event has been held annually ever since.[15] In 1926, Princess Mary became the commandant-in-chief of the British Red Cross Detachments.[16][5]

In the 1920s, she was a patron of the Leeds Triennial Musical Festival.[17] By the 1940s, Princess Mary was attending the opening nights and many of the festival's performances, as was her son, George, and his wife, the Countess of Harewood, née Marion Stein, a former concert pianist.[18][19] George was a noted music critic whose career included the role of artistic director of the Leeds Triennial Musical Festival.[20]

In 1931, she was appointed patron of the Yorkshire Ladies Council of Education.[21]

Newspapers from December 1933 record that committee member Miss Elinor G. Lupton launched "The Infirmary Appeal" with "the Princess Royal" agreeing to "become Patron of the whole Appeal" - supporting the "scheme" of fundraising for the Leeds Infirmary. The committee's Vice-Presidents included Mary's sister-in-law the Hon. Mrs Edward Lascelles. Other women "serving on the Committee" included Mrs Noel Middleton, Lady Burton and Miss J.B. Kitson.[22] Mary became patron of the Leeds Infirmary in 1936.[23]

A 1922 wedding portrait of Princess Mary and Viscount Lascelles.

On 28 February 1922, Princess Mary married Viscount Lascelles,[24] the elder son of The 5th Earl of Harewood and Lady Florence Bridgeman, daughter of The 3rd Earl of Bradford of Weston Park. The Princess was 24, Lord Lascelles was 39.

Their wedding was held at Westminster Abbey, and attracted large crowds along the route between Buckingham Palace and the abbey. The wedding was reported by Pathé News, including the appearance of the couple on the palace balcony.[25] The ceremony was the first royal wedding to be covered in fashion magazines such as Vogue. The wedding dress was created by Messrs Raville and combined "youthful simplicity with royal splendour". It was designed to reflect "Britain's position as ruler of a vast empire; emblematic lotus-flower motifs embroidered in India featured alongside a domestic, yet equally symbolic, trellis work of roses in pearls and crystal beads."[26] The Princess refused to share details of her honeymoon with the press.[26]

It was the first royal occasion in which Lady Elizabeth Bowes-Lyon (later Queen Elizabeth of the United Kingdom ), a friend of Princess Mary, participated. She was one of the bridesmaids.[27]

The bride's attendants were:

• Lady Elizabeth Bowes-Lyon (later Queen Elizabeth The Queen Mother)
• Princess Maud of Fife, daughter of Louise, Princess Royal
• Lady Mary Cambridge, daughter of The 1st Marquess of Cambridge
• Lady May Cambridge, daughter of The 1st Earl of Athlone and Princess Alice of Albany
• Lady Diana Bridgeman, daughter of The 5th Earl of Bradford
• Lady Mary Thynne, daughter of The 5th Marquess of Bath
• Lady Rachel Cavendish, daughter of The 9th Duke of Devonshire
• Lady Doris Gordon-Lennox, daughter of The 8th Duke of Richmond and Gordon.

Princess Mary and Lord Lascelles had two sons:[28]

• George, 7th Earl of Harewood (7 February 1923 – 11 July 2011); married, 1949, Marion Stein; had issue; divorced 1967; married, 1967, Patricia Elizabeth Tuckwell; had issue.
• The Honourable Gerald Lascelles (21 August 1924 – 27 February 1998); married, 1952, Angela Dowding; had issue; divorced 1978; married Elizabeth Collingwood; had issue.

The Princess and her husband had homes in London (Chesterfield House, Westminster) and in Yorkshire (first Goldsborough Hall, and later Harewood House).[29] While at Goldsborough Hall, Princess Mary had internal alterations made by the architect Sydney Kitson, to suit the upbringing of her two children and instigated the development of formal planting of beech-hedge-lined long borders from the south terrace looking for a quarter of a mile down an avenue of lime trees. The limes were planted by her relatives as they visited the Hall throughout the 1920s, including her father George V and her mother Queen Mary.

After becoming the Countess of Harewood on the death of her father-in-law, Princess Mary moved to Harewood House and took a keen interest in the interior decoration and renovation of the Lascelles family seat.[6][29] In farming pursuits, Princess Mary also became an expert in cattle breeding.[30] In December 2012, some of the Princess's belongings were sold in "Harewood: Collecting in the Royal Tradition", an auction organised by Christie's.[30][31]

Princess Mary by James Jebusa Shannon, 1914

On 6 October 1929, Lord Lascelles, who had been created a Knight of the Garter upon his marriage, succeeded his father as 6th Earl of Harewood, Viscount Lascelles, and Baron Harewood. The couple's elder son assumed the courtesy title of Viscount Lascelles. On 1 January 1932, George V declared that his only daughter should bear the title Princess Royal, succeeding her aunt Princess Louise, Duchess of Fife who had died a year before.[32]

The Princess Royal was particularly close to her eldest brother, the Prince of Wales, who subsequently became Edward VIII (who was known as David to his family). After the abdication crisis, she and her husband went to stay with the former Edward VIII, by then created Duke of Windsor, at Enzesfeld Castle near Vienna. Later, in November 1947, she allegedly declined to attend the wedding of her niece, The Princess Elizabeth, to Lieutenant Philip Mountbatten to protest against the fact that the Duke of Windsor had not been invited.[33] She gave ill health as the official reason for her non-attendance.[34]

The Princess Royal on a visit to Belfast City Hall, 13 October 1928

At the outbreak of World War II, the Princess Royal became chief controller and later controller commandant of the Auxiliary Territorial Service (ATS, renamed the Women's Royal Army Corps in 1949).[35][36] In that capacity she travelled Britain visiting its units, as well as wartime canteens and other welfare organisations.[35] On the death of her younger brother, the Duke of Kent, she became the president of Papworth. The Princess Royal became air chief commandant of Princess Mary's Royal Air Force Nursing Service in 1950 and received the honorary rank of general in the British Army in 1956.[35] Also, in 1949, the 10th Gurkha Rifles were renamed the 10th Princess Mary's Own Gurkha Rifles in her honour.[37]

After her husband's death in 1947, the Princess Royal lived at Harewood House with her elder son and his family. She became the chancellor of the University of Leeds in 1951, and continued to carry out official duties at home and abroad. She attended the coronation of Queen Elizabeth II in June 1953 and later represented the Queen at the independence celebrations of Trinidad and Tobago in 1962, and Zambia in 1964.[38] One of her last official engagements was to represent the Queen at the funeral of Queen Louise of Sweden in early March 1965.

The Princess Royal visited her brother, the Duke of Windsor (formerly King Edward VIII) at the London Clinic in March 1965, where he was recovering from recent eye surgery. The Princess also met her brother's wife, the Duchess of Windsor (at that time, married to the Duke for more than 28 years), one of the Duchess's few meetings with her husband's immediate family up to that time.

On 28 March 1965 the Princess Royal suffered a fatal heart attack during a walk with her elder son, Lord Harewood, and his children in the grounds of the Harewood House estate. She was 67 years old. She was buried in the Lascelles family vault at All Saints' Church, Harewood, after a private family funeral at York Minster. A memorial service was held at Westminster Abbey, London.[39]

Six British monarchs reigned during Princess Mary's lifetime: Victoria (her great-grandmother), Edward VII (her grandfather), George V (her father), Edward VIII and George VI (her brothers) and Elizabeth II (her niece). She is usually remembered as an uncontroversial figure of the royal family.[30] The Princess was portrayed by Kate Phillips in the film version of Downton Abbey (2019).