Edgar de Wahl

Edgar von Wahl or Edgar de Wahl (23 August 1867 – 9 March 1948) was a Ukrainian-born Estonian teacher, mathematician and linguist. He is most famous for being the creator of Occidental, a naturalistic constructed language based on the Indo-European languages, which was initially published in 1922. An Estonian of ethnic Baltic German origin, he studied in Saint Petersburg and spent most of his later professional life in Tallinn, Estonia.
He was born at Olwiopol, Russian Empire (now part of Pervomaisk, Mykolaiv Oblast, Ukraine).
At first an adherent of Volapük, de Wahl later became one of the first users of Esperanto and advised Ludwig Zamenhof on some points of grammar and vocabulary of that language. After several years he abandoned Esperanto, and in the following decades he worked on the problem of the ideal form of an international auxiliary language.
In 1922 he published a "key" to a new language, Occidental, and the first number of a periodical entitled Kosmoglott (later Cosmoglotta), written in that language. In following years, de Wahl participated in discussions about Occidental, and allowed the language to develop gradually as a result of the recommendations of its users. After World War II started in 1939, he had only intermittent contacts with the Occidentalist movement, which had become centred in Switzerland. He became a member of the Committee of Linguistic Advisors, part of the International Auxiliary Language Association, which would present Interlingua in 1951.
The last years of his life were spent in a sanatorium in Tallinn, Estonia, where he died in 1948. Shortly afterwards, in 1949, the name of Occidental was changed to Interlingue. Later, in 1951, Interlingua was unveiled; this led to the present insignificance of Interlingue (Occidental).