Born into a modest landowning family in Komárov—a small settlement in Bohemia—Kateřina’s fortunes transformed dramatically through her marriage to Jan Bechyně of Lažany, the powerful burgrave of Karlštejn, residing alternately in Pičín and Příbram. Although Kateřina’s own lineage was relatively undistinguished, her union with Jan Bechyně elevated her into a prominent noble family with significant influence.

As her husband supervised affairs at Karlštejn Castle, governance of the private domains fell to Kateřina—particularly during his prolonged absences. Her rule over the serfs became notoriously harsh: she imposed draconian punishments, including torture, leading not only to physical suffering but, in numerous instances, to death. Survivors bore lasting injuries, both mental and physical, long after their ordeals

By 1533, reports of Kateřina’s brutality had reached the Dean of the Karlštejn chapter, Wenceslaus Hájek—who would later become a respected chronicler. He relayed the alarming rumors to her husband, Jan Bechyně, who initially dismissed them as provocations and retaliated by suing Hájek. Undeterred, the matter was brought before a tribunal chaired by Vojtěch I of Pernštejn, convening sessions in Pičín to examine the allegations. At first, terrified serfs testified in favor of Kateřina, portraying her as benevolent. This changed when a Prague citizen—safe from reprisals due to being beyond her jurisdiction—publicly accused Kateřina of murdering his relatives. His bold testimony emboldened other survivors to come forward with the truth.

Under mounting evidence, Kateřina confessed to the murder of 14 serfs. Yet whispers circulated that the death toll may have been as high as 30 victims, per accounts from some servants.

In what was considered an unusual sentence for that era, the tribunal decreed that Kateřina should not face execution by conventional means. Instead, she was immured—imprisoned in a high tower at Prague Castle (Mihulka Tower) and left to starve as a form of punishment. She died there on March 15, 1534. Intriguingly, two days later, her judge, Vojtěch I of Pernštejn, also passed away—a coincidence that sparked rumors suggesting she had "dragged him down with her". Her husband, Jan Bechyně, weathered the scandal with minimal impact. He retained influence and was later appointed as a high scribe, maintaining his position until his death in 1547.