In Spain in 1936 an attempted military coup against the elected Republican government quickly escalated into a civil war between the Republicans (representing the centre and far left) who saw it as a struggle between democracy and fascism and the Nationalists (representing a coalition of army, the Catholic church, monarchists and conservatives) who saw it as a struggle against communism, anarchy and secularism. From the beginning atrocities were committed by both sides. Republicans slaughtered known supporters of the Nationalist cause, many of them Catholic priests and nuns, and the reprisals and revenge killings by Nationalist supporters were equally brutal.
As the conflict developed so the scale of destruction and the massacres of civilians and prisoners of war intensified. Taking into account the numbers of deaths in battle, executions, reprisals, revenge killings and deaths from starvation and disease, as well as the executions after the Nationalists had overthrown the Republican government, it has been estimated that around 750,000 people died directly or indirectly as a result of the civil war.
In some respects the tactics used by both sides, particularly aerial bombing and the terrorising and massacre of civilian populations, proved to be a rehearsal for what happened in the Second World War. What is particularly interesting, however, is that both sides continued to claim that they were abiding by the Geneva Conventions and that the atrocities were spontaneous actions by individuals and groups and not part of any planned policy. This has continued to be the case around the world in most internal conflicts since 1949.