The estimated �70m fortune includes works of art and house contents, the most important of which will go on public view.

It comes largely from investments including paintings, a valuable Faberge egg collection, china, jewellery and horses.

A special legal clause exempts the Queen from paying inheritance tax on the estate, but bequests from the Queen Mother to staff and other family will be taxed.

Inheritance from a 'sovereign to sovereign' or the consort of a sovereign to a reigning monarch is exempt from the 40% tax, above a �250,000 threshold.

This was agreed with former Conservative Prime Minister John Major in 1993.

He accepted it in recognition of the need for the sovereign to avoid erosion of the Royal Family's wealth.

A Buckingham Palace spokesman said: "Queen Elizabeth the Queen Mother has bequeathed her entire estate (which mainly comprises the contents of her houses) to the Queen.

"In her will, she asked the Queen to make certain bequests to members of her staff and these will be subject to Inheritance Tax in the normal way."

Trust

The Queen has decided the most important of her mother's pictures and works of art should be transferred to the Royal Collection.

This is held in trust for the nation.

Some of these items, including works by Monet, Nash and Carl Faberge, will be on display in the new Queen's Gallery, at Buckingham Palace, from 22 May.

In 1994, the Queen Mother reportedly put aside two-thirds of her money into a trust fund for her great grandchildren.

Princes William and Harry will reportedly share about �14m from the estate of their late great grandmother.

The bulk of the cash will go to the younger brother, since William will benefit financially by becoming king.

There will also be a shuffle of royal residences following the Queen Mother's death.

The Prince of Wales is expected to move from St James's Palace to Clarence House, the Queen Mother's former London home.

It will become his office and official residence in the capital.

The ground floor of Clarence House will be opened to the public during August and September in future years once refurbishment is complete.

The Duke of York could leave Sunninghill Park and move to Royal Lodge, the Queen Mother's former Windsor residence.

The Prince of Wales will continue to use Birkhall, a residence on the Queen's private Balmoral estate, which had also been made available to the Queen Mother.