Edgar Alexei Robert von Wahl or de Wahl (23 August 1867 – 9 March 1948) was a Baltic German teacher, mathematician and linguist.
He is most famous for being the creator of Interlingue, a naturalistic constructed language based on the Indo-European languages, which was initially published in 1922.
He was born at Olwiopol (according to some sources in Bohopil, a town nearby), Kherson Governorate, Russian Empire (now part of Pervomaisk, Mykolaiv Oblast, Ukraine).
The family spent some years in Ukraine, since the father of Edgar von Wahl worked there as a railway engineer.
After that the family stayed some years in Tallinn and moved then to Saint Petersburg.
Wahl studied there and began after that service in Imperial Russian Navy.
Since 1894 Wahl worked as a teacher in Tallinn.At first an adherent of Volapük, de Wahl later became one of the first users of Esperanto in 1888 and advised L.
L.
Zamenhof on some points of grammar and vocabulary of that language.
After several years he abandoned Esperanto after the failed vote to reform the language in 1894 (de Wahl was one of the few that voted for a completely new reform), 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 psychiatric hospital 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.