William III and Mary II were co-monarchs of England, Scotland, and Ireland from 1689 until Mary’s death in 1694. They came to power after the Glorious Revolution, which saw them replace Mary’s father, James II, due to his unpopular Catholic policies. Their reign marked a significant shift towards constitutional monarchy. William and Mary are known for establishing the Bill of Rights in 1689, which limited the powers of the monarchy and laid the foundation for a parliamentary system. Their rule helped solidify Protestantism in England and fostered a more stable political environment, influencing future governance.