Decoding the secrets of Queen Elizabeth's purse

For nearly as long as the Queen has been in the public eye, so have her many purses.

Unlike her subjects, who must keep keys and wallets and other essentials on hand, Elizabeth has no such mundane needs. Buckingham Palace's doors are always open to her, and she travels with attendants who keep her supplied with tissue, extra glovesand whatever else she might require. Nonetheless, wherever the Queengoes, herpurse goes with her.

The purse's biggest secret mightnot be what's inside, though, but where it'spositioned. Just like you've seen in your favourite spy films,Queen Elizabeth is said to use her purse to discreetly signal her staff, shifting its locationto let them know when she needs to be rescued from an awkward conversation.

This weekend,representatives from across the Commonwealth will celebratethe Queen's 90thbirthday with the Trooping the Colour parade and other public festivities.CBC News will bring youspecial coverage from Londonall weekend long.

• The Queen's 90th birthday: National service of thanksgiving
• How the Queen's fashion strengthens foreign ties
• Send usyour birthday wishes for the Queen