12. The False Demetrius II
The turmoil of Russia’s Time of Troubles produced another audacious pretender: False Demetrius II. Claiming to be the rightful heir, he rallied Cossacks and received substantial foreign backing, even establishing a rival court and controlling key territories. At his peak, he posed a serious threat to Moscow’s legitimate rulers, and his campaign prolonged the chaos engulfing Russia. Though ultimately defeated, his near-success demonstrates the era’s extreme instability. Britannica
