Roger David Casement (1 September 1864 – 3 August 1916), known as Sir Roger Casement CMG between 1911 and 1916, was a diplomat and Irish nationalist. He worked for the British Foreign Office as a diplomat and later became a humanitarian activist, poet and Easter Rising leader.
Described as the "father of twentieth-century human rights investigations", he was honoured in 1905 for the Casement Report on the Congo and knighted in 1911 for his important investigations of human rights abuses in Peru.
After retiring from consular service in 1913, he became more involved with Irish republicanism and other separatist movements. During World War I he made efforts to gain German military aid for the 1916 Easter Rising that sought to gain Irish independence.
He was arrested, convicted and executed for high treason. He was stripped of his knighthood and other honours.Roger Casement in Wikipedia