Koestler was sentenced to death under the regime of which Spanish military dictator?
Koestler Trust:  In Spain, he was sentenced to death in 1936 for espionage under Francisco Franco's regime. Francisco Franco: Francisco Franco Bahamonde (] ; 4 December 1892 – 20 November 1975) was a Spanish general who ruled over Spain as a military dictator from 1939 until his death in 1975.
Francisco Franco Bahamonde