Roger Casement may not be a household word in the United States, but those in Ireland and the Democratic Republic of Congo know very well who he is. Casement was one of the first modern humanitarians, a champion for the downtrodden of colonialism who got himself executed for his efforts in his native land. Martin Duberman has written a highly fact-based biographical novel called Luminous Traitor about Roger Casement and his efforts. Not downplaying or minimizing Casement's unorthodox sexuality, this book does an excellent job of illuminating Casement's thinking and the forces swirling around him. Of course, if you find Duberman's tome too dense (it is not a quick read) or want to know more about Casement's life and times, I do have suggestions.
For a slightly more fanciful take on Casement's life, there's The Dream of the Celt by the acclaimed Mario Vargas Llosa. The author chronicles Casement's transition from dutiful Foreign Service agent to rebel for indigenous peoples and on to his execution as a patriot. Fast-paced, with Vargas Llosa's usual deftness with character and plot, this book explains the author's popularity.
For those interested in the history of the Congo Free State outside of Roger Casement's involvement, Adam Hochschild's award-winning King Leopold's Ghost is a modern classic. The tragedy of central Africa under the rapacious auspices of Leopold II of Belgium and the equally violent aftermath that continues to this day is presented with passion and clarity.
As for primary sources as to what it was like on the ground in the Congo Free State, Joseph Conrad's fictionalized account, Heart of Darkness offers a good idea. While some attitudes the author displays are now dated, the outrage is palpable in this classic novella.
Casement couldn't understand why his efforts to raise a brigade of volunteers for Irish independence among WWI POWs were unsuccessful. A Long Long Way by Sebastian Barry might help explain. The novel follows a young Irishman as he fights for England but whose loyalties are divided by the Easter Rising. This is a sad, disquieting novel of the senselessness of war.
Morgan Llywelyn writes of pivotal years in Irish history, and 1916 covers the Easter Rising and is considered one of the best entries in the series. While using a fictional character as the focus, the major names of the Rising (including Casement) all make an appearance and Llywelyn manages to keep a story that could have been chaotic, coherent.
Jamie O'Neill writes of comraderie and unconventional love in At Swim, Two Boys. A middle-class boy and a poor one meet at a public beach in 1915 and agree to swim far out into Dublin Bay on Easter Sunday the next year. They fall in love despite their differences and the world's disapproval in this moving, linguistically complex novel.
Have more books on fighting the might of colonialism? Share them in the comments.