Montagu Christie Butler (25 January 1884 – 5 May 1970) was a British academic, librarian, lexicographer, musician, and Esperantist. A winner of several prizes at the Royal Academy of Music in London, he was a harpist and a versatile music teacher skilled in playing various musical instruments, as well as a teacher of voice and of musical composition.
As a Quaker and absolute pacifist, Butler was classed as a conscientious objector during World War One.[1] He served time in prison, where he met the composer and fellow prisoner Frank Merrick, helping him learn Esperanto.
From 1922, Butler was a member of the Lingva Komitato, the group tasked with preserving the fundamental principles of the Esperanto language and guiding its evolution. From 1916 to 1934, he served as secretary of the Esperanto Association of Britain, and was its honorary president from 1961 until 1970. Butler was later elected a member of the international Academy of Esperanto, where he served from 1948 until 1970.