28 September 2020
A fifth column is a group of insurgent forces engaging in sabotage and espionage behind enemy lines. The phrase dates to 1936 and the Spanish Civil War. In October of that year, fascist forces under Francisco Franco were advancing in four columns on Madrid, held by socialist government forces, and the fascists claimed to have a quinta columna working within the city. The Spanish term is variously attributed to both Franco and his deputy, Emilio Mola, but no one has been able to identify the original Spanish use of the phrase.
The phrase first appears in English in Associated Press stories about the war. From 10 October 1936:
The Socialist newspaper Informaciones in Madrid said Fascists had claimed assistance from a “fifth column inside the capital.”
(Dispatches concerning the “inside” column were cut drastically by the Spanish censor although indications were given that mass arrests of Fascist suspects followed the newspaper’s story.)
And a few days later on 16 October 1936:
Repeated claims by Gen. Francisco Franco, commander-in-chief of the Insurgent Forces, that a secret “fifth column” of Fascist sympathizers has been organized in Madrid—ready to aid Franco’s four lines of marching men when the assault on Madrid begins—led the Socialist Government to launch today’s raids.
The alleged fifth column was reported on widely in English-language newspapers in the fall of that year, and the term got a boost in 1938 with the publication of a play titled The Fifth Column set during the war by Ernest Hemingway and an anthology of that title that contains the play and forty-nine short stores. The play is not considered one of Hemingway’s finer works.
By the time World War II broke out in Europe in 1939, fifth column was being used generally to refer to insurgent forces operating behind enemy lines.
Sources:
Associated Press. “Rebels Cut Last Madrid Rail Line to East Coast.” St. Louis Post-Dispatch, 10 October 1936, 1. ProQuest.
———. “Rebels Rumble into Range for Madrid Attack.” Daily News (New York), 16 October 1936, 22. ProQuest Historical Newspapers.
Oxford English Dictionary, second edition, 1989, s.v. fifth column, n.
Notes:
When searching ProQuest, I became very excited when I found what was purported to be a use of fifth column in reference to Spain in Foreign Affairs from January 1936, before the Spanish Civil War had even started. This would have disproven the common explanation of the term’s origin. But upon checking the article in JSTOR, I discovered that ProQuest had bad metadata and the article actually appeared in July 1937. Lesson: always doublecheck the metadata.
Also, the Wikipedia article for fifth column had a reference, with citation, to a use of the phrase in a German diplomatic cable from 1906 in regard to the Balkans. But upon checking the reference the phrase does not appear. The term in the cable was politische Minierarbeiten (political mine-work/undermining), fifth-column-like activity, but not a use of the phrase and an entirely different metaphor. Such acts of sabotage and espionage have been going on since time immemorial, so citing this in reference to fifth column is uninformative at best and misleading at worst. I edited the Wikipedia page to delete the reference. Lesson: whenever possible go to the primary source.