King Charles holds the record of longest-serving monarch-in-waiting in British history, surpassing Edward VII’s record of 59 years. At the same time, he’s the eldest person to be crowned king in Britain. When he witnessed his mother becoming the head of the monarchy, King Charles was a three-year-old boy. Back then, he was totally unaware that one day he would be the one overtaking the monarchy. That day arrived with the passing of his mother, late Queen Elizabeth II, who ruled the country for over 70 years. Her reign spanned 14 US presidencies, from Truman to Joe Biden, and met all but one.