This is an edition of the previously unpublished Armenia section written by Count Eduardo Soderini (1853-1934) in his work The Pontificate of Leo XIII (1878-1903), of which sections on 1) the Conclave, 2) Politics with Italy and France, and 3) Politics with Germany have already been published. The first chapter presents the work of Leo XIII in favor of the preservation of the ritual heritage of the Eastern churches. The other four chapters form a report on the tragic events, known as "the Hamidian Massacres," which struck the Armenians in the Ottoman Empire from 1894 to 1896.