

While working as a journalist with the League of Nations in the 1930s she acquired a considerable affinity with the plight of pre-war Czechoslovakia.

She was imprisoned by the fledgling Free State government in 1922, during the Civil War, and served time in both Mountjoy and Kilmainham Gaols. When the republican movement split in 1921-22 over the Anglo-Irish Treaty, MacArdle sided with Éamon de Valera and the anti-Treaty Irregulars. In 1918 (during the War of Independence), Macardle was arrested by the RIC while teaching at Alexandra she was eventually dismissed in 1923, towards the latter end of the Irish Civil War, because of her anti-Treatyite sympathies and activities. Macardle was a member of the Gaelic League and later joined Cumann na mBan in 1917. Upon graduating, she returned to teach English at Alexandra. She received her secondary education in Alexandra College, Dublin – a school under the management of the Church of Ireland – and later attended University College, Dublin. Dorothy Macardle was born in Dundalk, Ireland in 1889 into a wealthy brewing family, famous for their Macardle's Ale, and was raised Roman Catholic.
