Jack had grown up comfortably, but the sudden loss of her father in childhood meant her early life was not without turmoil. She was a lively music-hall performer, known for her good humour and dapper attire. She famously acted as chauffeur to Mrs Pankhurst, driving her around Britain in an era where female motorists were not common.

Eve grew up with all the privilege and finery of a wealthy Scottish aristocratic family – one which, Moore points out, had owned slaves. She had been married twice and widowed young. A keen traveller, she had toured the world with relatives but was unafraid to strike out alone.

In 1895, in her late twenties, Eve sought adventure in Mexico and across North America: hiking to the summit of Glacier Point alone despite being warned against it and visiting an opium den in Los Angeles’ Chinatown. Her sense of adventure was shared by Jack.

The women met at a suffrage campaign meeting at the Albert Hall in 1908 and began a relationship that would last the rest of their lives as they came to regard each other as ‘twin souls’. Moore’s account of their relationship is thoroughly well-researched, informed by a myriad of collections of personal papers and imbued with insights from diaries and correspondence.

Moore weaves the narrative of Jack and Eve’s early relationship and the suffragette movement together seamlessly. Both women became engaged in increasingly militant actions and both spent time in Holloway Prison. Subsequently, they distanced themselves from the WSPU and Eve advocated for non-militant tactics as a founding member of the United Suffragists.

The biography moves on to chronicle their experiences throughout the First World War. Both women made significant contributions, organising women on the home front throughout 1914-15 and then undertaking humanitarian work through the Scottish Women’s Hospitals (SWH) in Serbia, Romania and Russia. The women faced difficult and often dangerous conditions and were imprisoned again, this time by the German Imperial Army.

The book details the work of the SWH and Jack and Eve’s places within in in great detail. The reader is captivated by rich descriptions of the dire conditions the women endured and events they witnessed. We follow their retreat through Romania in late 1916 and learn of the changing relationship between the SWH and their Russian allies as the Revolution unfolded.

Throughout, Moore portrays Jack and Eve as pioneers. Pioneers not only in their work for women’s rights and their commitment to humanitarian causes, but also in their open commitment to one another. It is heartening to read a biography that so frankly celebrates queer women and the steadfast joy they found in each other, even in the most tumultuous of circumstances.

Jack and Eve: Two Women In Love and At War by Wendy Moore. Published by Atlantic Books, 400pp, £22.