Hojo Tokimasa vs Olga of Kiev

Hojo Tokimasa became the first shikken (regent) of the Kamakura shogunate, serving under Shogun Minamoto no Sanetomo. This established the Hojo clan's control over the shogunate, reducing the Minamoto shoguns to figureheads.

Tokimasa conspired to depose Shogun Minamoto no Yoriie, his own grandson, accusing him of plotting rebellion. Yoriie was placed under house arrest and later assassinated, allowing Tokimasa to install the more pliable Sanetomo as shogun.

Tokimasa plotted to assassinate Shogun Sanetomo and replace him with his son-in-law, Hiraga Tomomasa. The plot was discovered by Tokimasa's daughter, Hojo Masako, who forced him into retirement and exile as a monk.

After his failed coup, Tokimasa was forced to retire to a monastery in Izu Province, where he died in 1215. His downfall allowed his son, Hojo Yoshitoki, to take over as shikken, continuing Hojo dominance.

As regent, Olga avenged Igor's murder by deceiving and killing Drevlian ambassadors, then besieging and burning their capital, Iskorosten. She used birds carrying flaming materials to set the city ablaze, subjugating the tribe.

Olga implemented a system of fixed tribute amounts and designated collection points (pogosts) across Kievan Rus. This reform standardized taxation, reduced corruption, and prevented the arbitrary exactions that had led to Igor's death.

Olga traveled to Constantinople and was baptized into Christianity by Emperor Constantine VII and Patriarch Polyeuctus, taking the name Helena. She became the first ruler of Kievan Rus to convert to Christianity.