The fighting was between the Republicans, who were loyal to the Spanish Republic, and the Nationalists, a rebel group led by General Francisco Franco. The Nationalists prevailed and Franco would rule Spain for the next 36 years. The coup was supported by military units in Morocco, Pamplona, Burgos, Valladolid, Cádiz, Cordova, and Seville. However, barracks in important cities such as Madrid, Barcelona, Valencia, Bilbao and Málaga did not join in the rebellion. Spain was thus left militarily and politically divided. The rebels, led by General Franco, then embarked upon an almost three-year war against the government for the control of the country. The rebel forces received support from the Third Reich, the Kingdom of Italy, and neighboring Portugal, while the Soviet Union and Mexico intervened in support of the Republican side. Other countries, such as the United Kingdom and France, operated an official policy of non-intervention.
They made up a considerable portion of the socialist volunteers, with estimates putting the figure at over ten per cent. Many of them joined the International Brigades and the Popular Front to fight in the Spanish Civil War on the side of the Republicans. The leadership of the International Brigades considered forming an entirely Jewish brigade, but the high casualties made this impossible. However, a Jewish company, the Naftali Botwin Company, was formed within the Palafox Battalion.
National origin of volunteers
The table below displays the national origin of the Jewish volunteers in the International Brigades.
- Shimon Avidan – Palestinian Jew and future Israeli military officer.
- Robert Domany – Croatian Partisan and a People's Hero of Yugoslavia
- Gershon Dua-Bogen – Polish communist
- Fernando Gerassi – Turkish artist
- Kurt Julius Goldstein – International Brigader, Holocaust survivor, and author
- David Guest – Communist British mathematician and philosopher.
- Alfred Kantorowicz – banned German writer (also known as Helmuth Campe)
- Lou Kenton – British potter
- Artur Kerschner – Croatian student
- Bert "Yank" Levy – a Canadian who famously used his experience to teach the British Home Guard and wrote a text on guerrilla warfare His service in the Civil War was memorialized in a comic book.
- Vladimir Majder – Croatian Partisan and communist
- George Nathan – Chief of Staff of the XV International Brigade
- Abe Osheroff – American communist
- Valter Roman – Romanian politician
- Carlo Rosselli – headed the Matteotti Battalion
- Alfred Sherman – British journalist and adviser to Margaret Thatcher
- Jack Shulman – American communist
- Manfred Stern alias General Emilio Kléber
- Drago Štajnberger – Croatian Partisan and a People's Hero of Yugoslavia
- Saul Wellman – political commissar of the Lincoln Battalion and the Washington Battalion
- Milton Wolff – commander of the Lincoln Battalion
- Máté Zalka – Hungarian communist
- Karin Hofmeester and Lee Mitzman, Jewish Workers and the Labour Movement, 2004
- Hugh Thomas The Spanish Civil War, 2001. p. 577n3
- Zaagsma, p 17
- Sugarman, Martin. "Against Fascism – Jews who served in The International Brigade in the Spanish Civil War" (PDF). Jewish Virtual Library/Jewish Military Museum. p. 122. Retrieved January 26, 2012.
- Levine, Allan E. "Bert "Yank" Levy". American National Biography on line. Oxford University Press. Retrieved April 16, 2014.
- Levy, Bert "Yank"; Wintringham, Tom (Foreword) (1964) . Guerilla Warfare (PDF). Paladin Press. Retrieved April 15, 2014.
- "Jewish War Heroes" (Comic book). Canadian Jewish Congress. February 1944. Retrieved April 16, 2014.
- "Fare thee Wellman". Detroit Metro Times.
- Thomas, Hugh (2001). The Spanish Civil War (4th (revised and updated) ed.). New York: Modern Library. ISBN 9780804152167.
- Jewish Volunteers in the Spanish Civil War, Abraham Lincoln Brigade Archives. (2008).
- Internationalism & the Spanish Civil War, Abraham Lincoln Brigade Archives. (2008).
- Baxell, Richard (September 6, 2012). Unlikely Warriors: The British in the Spanish Civil War and the Struggle Against Fascism (Hardcover). London: Aurum Press Limited. p. 400. ISBN 1845136977.
- Lannon, Frances (2002). The Spanish Civil War, 1936–1939. Oxford: Osprey. ISBN 9781841763699.