The Duke of Cambridge waas also ful of praise for the portrait.
Prince William said:: "It's beautiful, it's absolutely beautiful."
The Cambridges later attended a private breakfast reception at the London gallery to mark the unveiling.
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A mild, windy and cloudy day with perhaps some brief breaks in the cloud. The cloud may be thick enough at times for light drizzle at times.
Mild, windy and mainly dry.
It's not Father Christmas' usual mode of transport but these young patients didn't seem to notice.