Only three sovereigns – Edward V, Mary I and Edward VIII, who abdicated in 1936 before the ceremony was held – were not crowned seated in the large oak chair.
But wear and tear has taken its toll since the royal seat, housed at Westminster Abbey, was commissioned by Edward I in 1300.
Much of its rich paintings, ornate gold gilt and glasswork has been lost over the centuries and the wood damaged by the graffiti of 18th and 19th century schoolboys.
Dr Tony Trowles, head of the Abbey Collection, said: “At first sight it looks an odd chair for a monarch to be sat in but it originally had foliage and birds and the image of a king.
“It’s a slightly battered object but what does survive is particularly fragile and needs to be stabilised.
“The work is really conserving the original medieval paintwork and gilding, much of which was lost over the centuries.”