The article describes arson trials at the Carniolan Regional Court in Ljubljana in the first half of the 19th century. A few cases of arson were the work of confused, resentful and mentally unstable individuals; at that period revenge arson committed by outlaws was a common occurrence. In contrast to others, these outlaws did not stop at empty threats but did indeed set the roofs of "traitors" ablaze. However, outlaws were not the only arsonists. The ranks of arsonists also included people with other motives. The article presents a case involving an insulted prostitute and an old retired farmer. A special case was the category of unstable arsonists, who today would receive different treatment than in the past. In the pre-March period, judges were already obliged to consider the mental disturbance factor; however, proving it was considerably more challenging than it is today.