Explanation:

Queen Elizabeth II, who passed away recently at the age of 96, ascended the royal Britain throne in the year 1952. As of now, she is the longest serving monarch, who reigned for 70 years. The Queen became the UK's longest-serving monarch in 2015, when she surpassed the record of Queen Victoria, who had ruled from 1837 to 1901. Her eldest son, Charles, succeeds her on the throne as King Charles III.