MADRID (Reuters) - Veteran British historian Paul Preston estimates 200,000 Spaniards were killed far from the front line in the 1936-39 Spanish Civil War, and thousands more in the ensuing decades-long dictatorship of Francisco Franco.
After a decade of research, Preston gives details in his latest of many books on the War and its aftermath, whose English title is "The Spanish Holocaust: Inquisition and Extermination in Twentieth-Century Spain."
"I cannot think of a word that better encapsulates the astounding level of suffering of civilians in the Spanish Civil War and after," Preston said in response to a question about the use of the word holocaust in the book's title.
"There was an awful lot of death and suffering that isn't actually quantifiable because we don't know all the names," he told Reuters during a tour to promote the Spanish version of the book, released earlier this month.
The English edition will be published in autumn 2011.
Preston said many previous histories had focused on violence in areas controlled by the Republican government, rather than by supporters of the 1936 military uprising which began the war and eventually installed Franco as dictator in 1939.
"Basically what I've done is produce the first major study of the whole thing which looks at both sides, the difference in scale and of intentionality," he said.
"It's also the first that's based on this colossal amount of material that's come out over the last 10 years."
The professor of contemporary Spanish studies at the London School of Economics found that as well as some 300,000 dead in battle, 50,000 people were killed in Republican areas, and 150,000 in areas controlled by Franco's troops.
He concludes that violence in Republican areas was a spontaneous response to a breakdown in law and order caused by the uprising, which was later stopped, whereas killing by Franco's supporters was premeditated, systematic and sustained.
Preston also uses what he calls "cinematic technique" to focus on individuals such as Pascual Fresquet, leader of the "Death Brigade" which in the early weeks of the war summarily killed hundreds in the northeastern region of Catalonia.
"He ran literally a charabanc called the Skull Car, "El Cotxe de la Calavera" (in Catalan), which went round from town to town killing who they could get away with, although in the end they were stopped," he said.
So many horrific killers emerged in the war that Preston is now working on a series of mini-biographies about them to be called "Monsters," including one Capt. Gonzalo de Aguilera.
"He's a guy who on the first day of the uprising lines up all the peasants on his estate, picks six at random and shoots them to let the others know who's boss."
In the early 1960s, Aguilera ended up killing both his sons, attempted to kill his wife and ended his days in a lunatic asylum.
"At the end of the war he's quite prominent, but obviously the whole thing, the brutalization leaves him a really bitter and twisted bloke."
Nazi Germany and Fascist Italy supported the 1936 uprising, and the Republican government later appealed to the Soviet Union for help, turning the war into what many historians have described as a dress rehearsal for World War Two.
The fiercely opposed ideologies drawn into the war sparked the imagination of a whole generation in Europe and it continues to sharply divide opinions to this day, especially in Spain.
"It's tragic, horrendous, It's also fascinating. Look at it, you've got Fascism, Communism, Anarchism, Freemasonry, Socialism," Preston said.
"You've got every "ism" you can imagine, and you've got walk-on parts for Stalin, Trotsky, Hitler, Mussolini."
The War still leaves a lot of work for historians to do, and Preston says he alone could work on another eight projects.
In addition to "Monsters," he has been working for years on a biography of Mussolini, like one he has already published about Franco.
Reporting by Martin Roberts, editing by Paul Casciato