J.R.Firth born (17-6-1890)

"a leading figure in British linguistics during the 1950s"
Studied history at U. of Leeds.
Joined the Indian Education Service during 1914-18 war,
then Professor of English at University of the Punjab until 1928.
Returned to teach in UK, first phonetics at UCL, then Professor of General Linguistics at School of Oriental and African Studies (University of London), 1944-56. Died 1960.
https://en.wikipedia.org/wiki/John_Rupert_Firth
Firth is always mentioned in histories of linguistics, but I've never had much success in grasping what was distinctive about his theories.
Crystal focuses on "context of situation", the non-linguistic context in which speaking takes place, which can have an important influence on what is said and how it is understood. I think most people take this for granted now, but Firth may have been the first 20th century linguist to emphasize it. (Crystal quotes from his 1937 book _The Tongues of Men_.)
Wikipedia describes an interesting WWII project he was involved in:
"In July 1941, before the outbreak of war with Japan, Firth attended a conference on the training of Japanese interpreters and translators and began to think of how crash courses might be devised. By the summer of 1942 he had devised a method of training people rapidly in how to eavesdrop on Japanese conversations (for example, between pilots and ground control) and to interpret what they heard. The first course began on 12 October 1942 and was for RAF personnel. He had used captured Japanese code books and other such material to draw up a list of essential military vocabulary and had arranged for two Japanese teachers at SOAS (one had been interned on the Isle of Man but had volunteered to teach, while the other was a Canadian-Japanese) to record sentences in which these words might be used. Trainees listened through headphones to recordings containing expressions such as 'Bakugeki junbi taikei tsukure' (Take up formation for bombing). At the end of each course he sent a report to Bletchley Park commenting on the abilities of each trainee. The trainees were mostly posted to India and played a vital role during the long Burma Campaign giving warning of bombing raids, and a few of them were undertaking similar duties on ships of the Royal Navy during the last year of the war."