A coup d’état in April 1918 resulted in the establishment of the so-called Ukrainian State led by Hetman Pavlo Skoropadsky. Most left-wing forces, including the SRs, opposed the Hetman, who depended on the German-Austrian army, which had gained control of Ukraine. To resist the foreign military administration, Yevhen Terletskyi joined the Insurgent People’s Secretariat and started training the underground combat groups. He was the mastermind behind the famous — and successful— assassination of field marshal Hermann von Eichhorn
, the commander of German troops in Ukraine. Not only was he the organiser, but he was actually involved in the actual operation. After that, Terletsky went into hiding, was arrested and sentenced to death by firing squad together with his brothers in arms. He was found half-dead but miraculously survived.