Stack, Mary Meta (‘Molly’) Bagot (1883–1935), founder of the Women's League of Health and Beauty, was born 12 June 1883, probably in Dublin, second daughter among four daughters and two sons of Charlotte Stack (née Thompson) (d. 1929) from Omagh, Co. Tyrone, and her husband Theodore Stack (d. 1909?), son of George Hall Stack, QC, of Mullaghmore, near Omagh, and Mary Stack (née Orpen) of Ardtully House, Co. Kerry; she was a niece of Charles E. H. Orpen (qv), and was a great-aunt of William Orpen (qv). Beatrice Orpen (qv), Richard Orpen (qv), and Goddard Orpen (qv) were also related, and George Hall Stack (qv) (1850–76) was probably a brother of Theodore.
Theodore Stack trained as a doctor in Dublin, but because of increasing deafness, even though he was still quite a young man, he was no longer able to practise. He went to Harvard to retrain as a dentist, and was largely responsible for establishing the Dublin Dental Hospital. In 1884 Stack was appointed the first professor of dentistry there, but in his late forties (c.1898) he suffered a stroke that left him paralysed and unable to work.
The family, supremely well connected in Irish protestant society, but somewhat impoverished, believed in educating girls for careers just as much as boys, and Molly, despite two serious illnesses, attended Alexandra School and College. Her recovery from rheumatic fever was helped by her discovery of the physical exercise regime developed by Mrs Josef Conn, and based on the ideas of Sir Frederick McCoy (qv) about training women to enhance their health, especially for healthy childbearing. Molly trained as a teacher of the Conn method, and set up classes in Manchester; she taught factory girls at night, and came to believe that exercise and physical fitness would enable working women to improve their lives very significantly.
During this time she became engaged to an intensely possessive medical student in Dublin, Albert McCreery, who according to Stack eventually threatened to commit suicide if she did not marry him. They married in a registry office in London in 1909, but the marriage was apparently never consummated and they did not live together. A few months later, during a family holiday in August 1909 in Portrush, Co. Antrim, she met again her third cousin, (Edward) Hugh Bagot Stack, and they fell in love. Determined to end her marriage, Molly accepted the role of the guilty party in the divorce case, and in keeping with the law of the day had to furnish evidence of her adultery. Her statement to her husband was published in the Irish Times, resulting in notoriety and shame for both Stack families, and Hugh Bagot Stack's mother insisted on a year's delay before their quiet wedding in the City Temple, London, on 10 March 1912.
The couple went to live in India; Stack was a captain in the 8th Gurkha Rifles. A baby boy died soon after birth in 1913, but their daughter Prunella was born on 28 July 1914. On 5 August 1914, on the outbreak of war, Stack's regiment was ordered to embark for France. During their first day in action in the trenches (1 November 1914) the Gurkhas were mown down; only two officers survived, and Hugh was killed. Molly Bagot Stack with her baby daughter had left India for England, and on arrival found his name in a list of casualties in newspapers that came on board ship.
She eventually resumed her teaching to make a living, but was dissatisfied with some aspects of the Conn system. Influenced by her experiences in India and some knowledge of yoga, she developed exercises that encouraged grace and relaxation as well as muscular strength; she called them ‘the Bagot Stack stretch and swing system’, and in her illustrated book on the subject, Movement is life (1931), she set out the theory as well as the practical aspects of her ideology. In her eyes, beauty and fitness were indivisible; she felt that increasing fitness to improve physical beauty would promote well-being in the individual and thence in society. She also believed that women should be educated so as to be aware of their physical potential, to be able to produce healthy children, and to see how body and soul could achieve harmony in bringing about and becoming part of a peaceful and spiritually fulfilling world community.
She was inspired in 1929 by reading about the Czechoslovakian youth movement to realise how the benefits of exercise and the work for world peace could involve many more women, and in 1930 she founded the Women's League of Health and Beauty. This developed quickly into an organisation that organised day and evening classes and trained teachers in premises in London. Members paid small yearly dues and 6d. (£0.025) per class; they wore uniforms and badges, made promises to improve their physical health, and took part in regimented exercises to music. Bagot Stack was an inspirational leader; she and her daughter were both beautiful, and were mesmerising speakers at public meetings, which sometimes seemed almost like choreographed rallies, though always decorous and ladylike. Loyal assistants, including some of her sisters and a niece, helped with teaching and organisation; finance was always difficult, especially while Stack was still in charge, because of her impulsive generosity and idealism. She had a genius for publicity, and organised impressive public displays of lightly-clad girls and older women doing exercises in unison, in Hyde Park annually for several years from 1930 and in Olympia and other venues. Belfast was the first provincial centre where the League organised, and more than 200 others soon followed; girls from all over Britain and Ireland were involved in putting on the displays in London during the 1930s.
The movement was not only phenomenally successful, it was also characteristic of the period. There were 170,000 members at the end of the League's first decade, in the UK, in Ireland, and in Commonwealth countries such as Australia and Canada, and even in Hong Kong; in the seventy-odd years since it was founded, hundreds of thousands of women have found comradeship, fun, and increased well-being through participation in the League's activities. Still in existence in the early twenty-first century, and known as the League of Fitness, it has outlasted many of the rival organisations and ‘lifestyle’ fashions which have all, more or less, derived inspiration from its success and from Bagot Stack's ideals.
In the same year that she founded the League of Beauty and Health, Molly Bagot Stack discovered a cancerous growth on her neck; after treatment, she continued her work for the new organisation with undiminished enthusiasm, even producing gramophone records of her teaching, but when thyroid cancer returned she was forced to hand over her responsibilities, including the organisation of that year's display, to her assistants and to her 20-year-old daughter. For the last six months of her life she was blind and in constant pain. She died on 26 January 1935. All Souls church in London, where a funeral service was planned, had to remain open all night to allow hundreds of League members to pay their respects; an obituary noted that ‘thousands of girls worshipped her . . . [on account of her] great personal charm . . . human sympathy . . .. [and] courage’ (Times, 2 Feb. 1935). Her body was cremated at Golders Green.