The first woman to rule as King of England was Mary I, also known as Mary Tudor. She ascended to the throne in 1553 after the death of her half-brother, Edward VI. Mary's reign was marked by her attempt to restore Roman Catholicism in England, reversing the Protestant reforms initiated by her father, Henry VIII, and her brother. Her efforts included the persecution of Protestant reformers, earning her the moniker "Bloody Mary." Despite her short reign, which lasted until her death in 1558, Mary I’s rule was significant in the history of England as it highlighted the complexities of religion, politics, and gender in monarchical power.