William IV of the Netherlands was born on September 18, 1792, and became king in 1840 after the abdication of his father, William I. He ruled until his death in 1849. His reign was marked by efforts to modernize the Dutch government and society, including the promotion of constitutional reforms. During his time as king, William IV faced challenges such as political unrest and the need for economic improvements. He was known for his commitment to the welfare of the Dutch people and worked to strengthen the monarchy's role in a changing political landscape.