The studio collection of the revered royal sculptor Angela Conner has emerged for sale for £100,000.
The British artist, who is nearing 90 and is retiring, is selling more than 50 works, including bronze busts of the late Queen and King Charles.
In a catalogue foreword, Queen Camilla expresses her 'awe' for Conner and laments that 'this great artist is laying down her tools', before adding that 'her work will inspire and delight for generations to come'.
The collection also features a rare bust of her friend, the iconic British artist Lucian Freud, who was notoriously reluctant to do sittings.
Other busts in the sale are of the James Bond author Ian Fleming, poet laureate Sir John Betjeman and actor Laurence Olivier.
Connor, who was an apprentice under St Ives sculptor Barbara Hepworth, was commissioned by the Knights of the Garter to create a 15ins tall portrait bust of Elizabeth II to mark her 80th birthday in 2006.
The Queen agreed to six sittings of two hours each which took place in the Chinese room at Buckingham Palace.
She was captured by Conner looking straight forward sporting a firm gaze, with a three-strand pearl necklace draped around her neck.
Ten busts were made, one of which is displayed at St George's Chapel in Windsor, and this example, numbered 'three', is tipped to fetch £12,000.
A bronze bust of Charles made in 1995, depicting the former Prince of Wales looking off into the distance, is valued at £6,000.
And a bronze study of his beloved Jack Russell Tigga, who died aged 18 in 2002, is expected to sell for up to £500.
A study of Camilla's rescue dog Beth - who she adopted from Battersea Dogs and Cats Home in 2011 - has the same estimate.
Freud only agreed to sit for a handful of sculptors who he particularly admired.
It reputedly took quite a while for her to persuade Freud to look her in the eye, but she persevered and he complied.
Conner said of working with Freud in a 2000 interview: 'You certainly have to get to know them; there's no question. You have to peel off the layers.'
His bronze bust, which was exhibited at the Chatsworth Theatre Gallery in 1975, could go for £30,000.
The collection, also featuring her abstract and kinetic sculptures, is set to spark a bidding war at Dreweatts Auctioneers, of Newbury, Berkshire.
The auction house said that 'sculpture pioneer' Conner is selling a selection of her works to celebrate her long-standing career.
Francesca Whitham, specialist at Dreweatts, said: 'It is a pleasure to offer the studio collection of Angela Conner, a pioneer in the field of sculpture, whose works will always have the ability to inspire and evoke emotion and fascination.
'Her ability to capture a person in clay, in such precise detail, is exceptional and I believe this is driven by her ability to feel an emotional connection to her sitters and allowing this interaction to take over the physical practice of modelling.
'What has become apparent over the last couple of months as I have spent time with Angela's works is the intense passion and determination that formed each piece.
'I have been particularly struck by Angela's close connection to nature, which sits at the core of her work.
'Whether this may be through the exploration of the effects of wind, the sun or experimenting with balance and forces - it is these elements and the way they are intertwined in Angela's work which makes it so exceptional.'
Conner, who has studios in Herefordshire and London, said of her career: 'I started making sculpture when all of us start making sculpture - as a child - with cardboard, paper and glue. I guess the difference is that I never stopped.'
Queen Camilla, in the catalogue foreword, said: 'I am delighted to introduce this wonderful collection of Angela's work which will, no doubt, evoke a mixture of emotions in us all.
'Admiration, awe, amusement, peace and joy are now tinged with the poignancy that, as she approaches her 90th birthday, this great artist is laying down her tools.
'From vast public installations to intimate bronze busts; from extraordinary abstracts to the perfect depiction of a horse poised for action - there is no feeling and no moment that Angela cannot capture.
'This world is enhanced by her talents and her work will inspire and delight for many generations to come.'
The sale takes place at Donnington Priory on July 11.