In 2014, following a grassroots activist campaign, the new bridge over the River Liffey was named after the revolutionary and trade union activist, Rosanna 'Rosie' Hackett (1893-1976). From an early age Hackett, a working-class Dublin woman, was involved in trade unionism, nationalism and the fight for women's rights. She was at various times a member of the Irish Women Workers' Union, the Irish Citizen Army and Cumann na mBan. She was involved in the 1913 Lockout, the 1916 Rising, the War of Independence; she spent over 50 years as a trade union activist working in Liberty Hall. Naming a major structure in the capital city after this 'unknown' woman honours the contributions of many other unknown women to modern Irish history. In this collection historians and activists bring to light more of those hidden histories of Irish women's political, militant and trade union activism.