In 1907 some time after Roger Casement's conversion to Irish nationalism, he reflected on the shift in his allegiance, in a letter to Alice Stopford Green: I had accepted Imperialism - British rule was to be extended at all costs, because it was the best for everyone under the sun, and those who opposed that extension ought rightly to be "smashed" ... Well the [Boer] War gave me qualms at the end - the concentration camps bigger ones - and finally when up in those lonely Congo forests where I found Leopold I found also myself - the incorrigible Irishman!' In that statement, Casement linked his growing anti-imperialism to his Irishness. In this paper I wish to examine three themes which also show the interrelatedness of Casement's wider experiences with his Irishness and which I believe to be important in summing up key patterns of thinking and action in his life: land and agriculture, the defence of the underdog, and a critique of empire. Each theme has roots in his youth, draws on his later Irish experience, and was affected and developed by his experiences outside Ireland.