Chetniks (from Serbo-Croat: četnik, armed band) were Serb guerrilla units. Formed in 1903, they also fought in the Balkan wars in 1912-13, usually behind enemy lines. They are best known today as the royalist irregular units under Col Draza Mihailović who carried on the fight for King Peter II after Germany invaded Yugoslavia on 6 April 1941. The Chetniks at first enjoyed the diplomatic and military support of the western Allies and Mihailović was named war minister by the royal government in exile. But from 1944, thanks partly to reports by Churchill's envoy Fitzroy Maclean, the Allies transferred their backing to the pro-Communist partisans of Josip Broz Tito. The Allies' principal accusation—never accepted by the Chetniks—was that they were collaborating with the Nazis. By 1945 many Chetnik fighters had switched sides, tempted by Tito's offer of an amnesty.
After Tito entered Belgrade in November 1944, the hunt was on for Mihailović, who was captured in eastern Bosnia, put on trial, and executed for treason. The large Serb émigré community mostly revere him as a martyr. The Chetniks claimed to be fighting for a united Yugoslavia and the Karadjordgevic dynasty, and against a communist takeover. In practice their support was confined to the Serbs and among the country's non-Serbian majority, fear of communism was often outweighed by anxiety that a Chetnik victory would result in a centralized state run exclusively by the Serbs. These fears appeared vindicated by atrocities committed against the Bosnian Muslims.
As Yugoslavia dissolved into its constituent units in 1991-2, the extreme Serb nationalist leader Vojislav Seselj attempted to revive Chetnik units, along with their distinctive black flags with white skulls and crossbones, to help the Yugoslav army suppress pro-independence forces in Bosnia and Croatia.
— Marcus Tanner
