Until now, in-depth analysis of key female figures in Irish republicanism in the early twentieth century has been limited. Mary MacSwiney was one of themost single-minded anti-Treaty women, leading Eamon de Valera to describe her as 'incorrigible'. Rather than just dismiss MacSwiney as one-dimensional in her opposition to the Treaty and in her continued political intractability, this biography seeks to place her political life within the centre of the turn of the twentieth-century republican narrative and understand why she was increasingly viewed as a virago.

To say contemporary gender roles played a part in reducing MacSwiney to a cipher for extreme republicanism limits a fuller understanding of her political life. Her uncompromising stance against the evils of compromise during the Treaty negotiations was indelibly formed by the experience of watching her brother Terence MacSwiney die on hunger strike in Brixton Jail in 1920, and the trauma she experienced. She witnessed an intimate act of self-sacrifice which bound her to a belief that her task was to continue her brother's fidelity to a separatist republic.

Betrayal of the republic, for her, would have meant betrayal of a brother she loved and admired. Mary MacSwiney situates this standout figure in the context of her tightly knit family, tracing her political evolution from suffrage and cultural revival activism to advanced nationalism. While the focus of MacSwiney's political action was Cork, from1920 onwards she began to assume a progressively more important role in Irish politics at a national and international level, including American tours, a central role during the Civil War and within Sinn Fein and a close political relationship with de Valera.

From 1926 onward, she was increasingly politically isolated and marginalised as she sparred with members of Fianna Fail in the press, seeking to justify her continued refusal to engage with the reality of the Irish Free State. Leading biographer of women in twentieth-century Irish history, Leeann Lane delves into newly discovered archival material to interrogate MacSwiney's oppositional stance to the establishment of the Irish Free State in 1922. Mary MacSwiney offers a comprehensive understanding of a misrepresented and marginalised voice in early twentieth-century Irish politics.