Who was the most cruelest queen in history?

One of the most notoriously cruel queens in history is often considered to be Queen Mary I of England, also known as "Bloody Mary." Her reign from 1553 to 1558 was marked by the persecution of Protestants, leading to the execution of hundreds in her efforts to restore Catholicism. Another contender is Empress Catherine the Great of Russia, who, despite her achievements, was known for her ruthlessness in consolidating power and her involvement in the suppression of uprisings. Both figures exemplify the darker aspects of monarchical rule.