Roger Casement

Sir Roger Casement (1 September 1864 – 3 August 1916) was an Irish nationalist and British diplomat. He served as British consul in Boma, the capital of the Congo Free State and reported human rights abuses there. He helped a campaign against King Léopold II of Belgium's rule in the Congo Free State which lead him to relinquish his African kingdom to the Belgian Parliament in 1908. He was an Irish revolutionary. After participating in the 1916 rising, he was executed for treason by hanging by the British.
His role in the rising was in the importation of guns, he was arrested in Tralee, County Kerry. 
At his trial he was outed as gay, this was discovered through his diary.