The historic document signed by the Queen to give her approval to her grandson's marriage has been unveiled.
Personally signed by the monarch, the elaborate document proclaims her consent to the union of "Our Most Dearly Beloved Grandson Prince William Arthur Philip Louis of Wales, K.G. and Our Trusty and Well-beloved Catherine Elizabeth Middleton".
The Prince had to ask his grandmother's permission in line with a law dating back to the 18th century.
Under the Royal Marriages Act 1772, all descendants of George II must obtain the sovereign's agreement before they wed, otherwise the marriage is invalid.
Known as the 'Instrument of Consent', the document features elaborate artwork representing the groom and bride-to-be.
There is a gold cipher of their entwined initials, beneath the prince's coronet.
A white lily represents St Catherine of Siena, whose feast day falls on April 29 and with whom Kate shares her name.
Beneath it is a Welsh leek surrounded by William's 'label', a symbol comprising three prongs which denotes his status as second in line to the throne.
The tiny red escallop - or sea-shell - comes from the Spencer family arms.
Also represented is a red dragon - the heraldic symbol of Wales, the UK's floral emblems - the rose, thistle and shamrock - and the Garter belt.
The Instrument of Consent will be presented to the royal newlyweds following their marriage as a keepsake.