Britain's Prince Charles "often" thinks about the "crazy" people who want to harm the Royal family.
Britain's Prince Charles
The heir to the throne, aged 67, revealed his fears after he watched old family footage during a BBC documentary to mark the monarch's 90th birthday, entitled 'Elizabeth at 90 - A Family Tribute', which aired on Thursday (21.04.16).
He described an incident that involved his mother, Queen Elizabeth II, leading the 'Trooping the Colour' - a ceremony performed by regiments of the British and Commonwealth - along The Mall in London.
The streets were lined with huge crowds cheering the monarch on as she rode horseback toward Buckingham Palace, when suddenly shots were fired.
Her son recalled: "Every year it's impeccably organised... I was riding behind her with my father and the Duke of Kent, the sound of shots came from the crowd. This chap, it turned out, fired blanks. But uh, you know, at the time..."
He continued: "It's one of those things you often think about - you know riding down The Mall at any minute - who might do something crazy, because there are all sorts of people about."
However, it wasn't the first attack on a member of the royal family at the location.
Seven years prior, Princess Anne was attacked nearby by a gunman and in 1936, her grandfather, King Edward VIII, faced a man with a loaded revolver.
And Queen Victoria - who died in 1901 - was also shot at by a man with a gun in The Mall.
However, the Queen is "made of strong stuff" and hardly flinched as she calmed her horse and continued on.
Charles added: "You must continue, that is the great thing, like ma'ma certainly did. But she is a marvellous rider. She's made of strong stuff."