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. 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. Upon graduating, she returned to teach English at Alexandra. Macardle was a member of the Gaelic League and later joined Cumann na mBan in 1917. 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. When the republican movement split in 1921-22 over the Anglo-Irish Treaty, MacArdle sided with Éamon de Valera and the anti-Treaty Irregulars. She was imprisoned by the fledgling Free State government in 1922, during the Civil War, and served time in both Mountjoy and Kilmainham Gaols. 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. Consequently she differed with official Irish government policy on the threat of Nazism, Irish neutrality during World War II, compulsory Irish language teaching in schools, and deplored what she saw as the reduced status of women in the 1937 Constitution of Ireland. Macardle recounted her Civil War experiences in Earthbound: Nine Stories of Ireland (1924). Macardle became a playwright in the next two decades. In her dramatic writing she used the pseudonym Margaret Callan. During this time she worked as a journalist at the League of Nations. She also researched her mammoth book The Irish Republic which was first published in 1937. Her political opponents and some modern historians consider her to be a hagiographer for de Valera's political views. Murray considers that: "..de Valera’s ambitious scheme was eventually implemented by Dorothy Macardle, his devoted follower and lifelong apologist, whose book The Irish Republic conforms closely to the overall plan outlined by de Valera in prison, and even incorporates many of its details. The outline originally proposed by de Valera was extremely detailed, incorporating a carefully planned chronology and headings from which the chapters were to be developed." She died in 1958 at the age of 69 of cancer in hospital in Drogheda. Though she was somewhat disillusioned with the new Irish State (in particular, regarding its treatment of women), she left the royalties from The Irish Republic to her close friend Éamon de Valera, who wrote the foreword to the book. De Valera visited her when she was dying.