Kate Middleton and Prince William are expecting their third child together, and the Duchess is due to give birth any day now.

She has stopped all royal engagements in preparation for the big day and won't return to her duties until the autumn.

Although Kate's exact due date has not been announced, it's possible it could be on or close to April 21, which is the Queen's birthday.

So what will happen if they share a birthday?

Well, according to Express, the palace would throw a joint cross-generational party.

The Queen usually spends her birthday privately, but the occasion is marked publicly by gun salutes in London at midday: a 21 gun salute in Windsor Great Park, a 41 gun salute in Hyde Park, and a 62 gun salute at the Tower of London.

If the baby is very late, she could end up being an anniversary present for the couple, who will have been married for seven years on April 29.

According to The Sun the due date is likely to be April 23, St George's Day - very patriotic altogether.