Born Alice Sophia Amelia Stopford in Kells, Co Meath, she lived in London where she met the historian John Richard Green. They were married in Chester on 14 June 1877. He died in 1883. John Morley published her first historical work Henry II in 1888.

In the 1890s she became interested in Irish history and the nationalist movement as a result of her friendship with John Francis Taylor. She was vocal in her opposition to English colonial policy in South Africa during the Boer Wars and supported Roger Casement’s Congo Reform movement.

In The Making of Ireland and its Undoing (1908), she contradicted the widespread English belief that Ireland had no civilisation apart from what had been borrowed from other countries, particularly England.

In 1913, she joined her friend Roger Casement in an unsuccessful effort to rally Protestant support for home rule, and in the following year chaired a committee which raised funds for the importation of arms from Germany into Ireland. Despite her involvement in this affair, she was essentially a constitutionalist, and for that reason disapproved of the republican uprising of 1916. Nevertheless, her nationalist commitment was unshaken: she took a leading part in the campaign for the reprieve of Roger Casement, sentenced to death for treason, and in the following year made the decision to move back to Ireland.

Stopford Green’s house at 90 St Stephen’s Green, Dublin became an intellectual centre, and she quickly established herself as a central figure in political and cultural life. A supporter of the Anglo-Irish Treaty which ended the War of Independence, she was a member of the pro-Treaty women’s organisation Cumann na Saoirse (League of Freedom) and a founding member of the political party, Cumann na nGael. Nominated to the first Irish Senate as one of four women members, she served on a committee to establish a scheme for the publication of Irish-language manuscripts, and supported W.B. Yeats’ call for the retention of the right to divorce. Meanwhile, she continued her researches in Irish history, her last work, Studies from Irish History, appearing in 1926 when she was 79.

She died in Dublin following a short illness, leaving behind her a body of work which, for good or ill, shaped the version of Irish history which predominated during the formative years of the new state.