If you die without a will and there are no surviving relatives who can inherit under the rules of intestacy, the estate passes to the Crown. This is known as bona vacantia. The Treasury Solicitor is then responsible for dealing with the estate. The Crown can make grants from the estate but does not have to agree to them.
So effectively the Royal Family have control over how your money is spent. Please make a will, especially if you have no surviving relatives who can inherit. Leave it all to a charity if you want but not the Royal Family.