Alratan, there's more to it than that...
...The head of the Royal Family reigns, she doesn't rule, as descendant of Sophia, the Electress of Hanover, with the consent of Parliament. The Queen owns Sandringham, Balmoral and a handful of other estates - Sandringham was bought with King George V's winnings on the horses. These are separate to the Crown Estates of which the Queen is symbolic owner and the income from which provides money for the Civil List. A typically British fudge.
The confusion of Crown Estates and Royal Family's actual possessions has been used by newspapers to claim that Queen Elizabeth is the richest person in Britain. The actual list for 2012 is on
http://www.therichest.org/nation/sunday-times-rich-list/ and the Duke of Westminster comes 7th with £7.3 billion. William and Harry are heirs to only £28 million in land. Rather paltry, don't you agree?
http://www.richest-people.co.uk/the-top-100/ offers another listing - and, again, where's the Queen?
http://www.forbes.com/2001/06/26/0626queens.html has a US slant ($$) but again is a poor $150 million in land in a total $ 420 million portfolio. Say, £200 million?
In brief, Richard Branson (£4.3 billion) could buy out the Queen from his loose change.