The longest-serving monarch of the United Kingdom is Queen Elizabeth II. She ascended to the throne on February 6, 1952, and has been reigning for more than 68 years. She surpassed the record set by her great-great-grandmother, Queen Victoria, on September 9, 2015. Queen Elizabeth II has been a prominent figure in British and world history, and her reign has witnessed significant changes in society and politics. Her longevity and dedication to the monarchy have made her a beloved and respected figure in the United Kingdom and beyond.