Harley explained that small-scale casts of Moore’s works often go to auction, but this large outdoor bronze was “an exceptional opportunity”.
“It’s a museum-quality piece. The other casts of this model are all in museum collections. So it’d be lovely to think it would go to a museum but it could be bought privately,” he said.
He added he was expecting international interest in the sale.
“Moore’s work has been very well regarded in the United States, certainly in Asia as well, but I think there’s some very deep collections in the United States,” he said.
“It is remarkable this one was bought 70 years ago directly from the artist and it stayed in the same family since then. So it’s got an incredible history.”
He added King and Queen was an important milestone in Moore’s work, because it marked a move towards placing bronze sculptures in a landscape setting.
“It was like a moment of realisation that his work could then go on to become larger scale and be placed outdoors,” he said.
King and Queen will go on display at Christie’s in London on Thursday prior to the auction next month.