Final answer:
Mary Tudor promoted Catholicism through repression and executing Protestants, but her efforts failed due to political opposition and the harshness of her policies.
Step-by-step explanation:
Mary Tudor, also known as Mary I and "Bloody Mary," attempted to restore Catholicism in England primarily through repressive measures. She repealed the legislation that had established the Church of England, which effectively reinstated the Pope's authority. Moreover, Mary resorted to the persecution and execution of several hundred Protestants, a time known as the Marian Persecutions. However, Mary Tudor's efforts to strengthen Catholicism failed largely because of political opposition and widespread resentment of her harsh and draconian religious policies. After her death, her half-sister Elizabeth I took the throne and sought a more moderate approach, balancing between Protestant and Catholic interests, thus restoring some stability to England.