In the case of ISIS, it was Sunni fighters who had been on the losing side of Iraq’s civil war who founded a state in Syria, then returned to Iraq to retake cities like Mosul from the Iraqi government—just as Ungern-Sternberg had planned to take Russia back from the Bolsheviks. Civil war provided the context in which both ISIS’s leaders and Ungern-Sternberg came to rely on systematic and highly visible atrocities to consolidate their rule, at a moment when years of savage, disorganized violence had desensitized populations. Like ISIS, Ungern-Sternberg harnessed this violence to establish a modicum of order.

In Mongolia, Ungern-Sternberg executed deserters and recruits who did not meet his expectations. Stories of the baron’s bloodlust abound, and the author Peter Hopkirk compiled some of the most sensational. Captives were allegedly buried alive, burned at the stake, and thrown into the boilers of trains. One witness asserted that in Ulaanbaatar, the baron sentenced a baker’s dishonest apprentice to be baked to death in his own oven. Another claimed that the baron hung three men accused of stealing brandy over the door of the shop they robbed … until the shopkeeper, worried about losing business, begged him to remove the bodies.

Contemporary biographers of Ungern-Sternberg have struggled to paint a reliable portrait of the man out of rumors and shaky sources. But the results do little to vindicate him. In trying to sort myth from reality, for example, the historian James Boyd argues that contrary to some reports, the baron didn’t allow rampant looting in Ulaanbaatar; he actually prevented it by immediately hanging looters. And Sergius Kuzmin of the Russian Academy of Sciences issues such remarkable corrections as, “Ungern maimed doctor Klingenberg not for the death of Bayar Gung at Kyakhta, but for not rendering medical assistance to wounded Chakhars.” The veracity of a particularly damning account by one of Ungern-Sternberg’s officers, Dmitri Alioshin, has also been hotly disputed. Alioshin accuses the baron of whipping men to death, burning them alive, and feeding them to wolves. But Boyd argues the wolves might be more of a literary trope. Another historiographical note, offered by Kuzmin in the baron’s defense, vividly captures the horror of the period: Alioshin’s memoirs “described the story of poisoning of wounded men in the field hospital by A.F. Klingenberg, as if it was ordered by Ungern. However, memoirs by Golubev and A.S. Makeev provided more reliable and detailed data: lieutenant colonel Laurentz, on behalf of the baron, ordered medical attendant Logunov to poison wounded men, for which he was shot by Ungern’s order.” Even the most cautious accounts, in other words, make clear that Ungern-Sternberg’s ruthlessness was real enough.

So too was the religious dimension of his exploits. During a pre-war visit to Mongolia, the baron had converted from Christianity to a strange form of mystic Buddhism. His never-fully articulated interpretation of the faith, with which he sometimes mixed bits of Christian eschatology, was probably just as bizarre to most Buddhists as ISIS’s strain of Islam is to Muslims today. But as Ungern-Sternberg amassed power, people found political and personal reasons to play along with his desire for religious legitimacy. One of his first moves after attacking Ulaanbaatar was to free Mongolia’s Buddhist leader and former king, the Bogd Khan, who was being held under house arrest by the Chinese. The Bogd Khan was a high-ranking member of the Tibetan Buddhist hierarchy and had his own political agenda in Mongolia, which he felt the baron might help him advance. And so the Bogd Khan bestowed an official blessing on the baron, granting religious sanction to Ungern-Sternberg’s rule. According to one of the more extravagant accounts, he endorsed the baron’s claim to being “the incarnated God of War and Khan of grateful Mongolia.” Other scholars render the title more modestly as “Great Hero General, Builder of the State,” or simply, “Hereditary Grand Duke Darkhan Khoshoi Chin Wang in the dignity of Khan.”