A rare portrait of Princess Diana just sold for 10 times more than auction house Sotheby’s was expecting.

The oil painting by the late Nelson Shanks was completed in 1994. The head study was created at the same time Shanks did a full-length painting which Diana commissioned.

Diana sat for over 35 hours while Shanks worked on the piece which was originally hung at her home in Kensington Palace. After her death, it was moved to her childhood home Althorp where her brother Earl Charles Spencer now lives.

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In the head study, Diana wore a green Catherine Walker halter dress with her eyes looking downward.

The painting was expected to bring in $20,000 but was sold for $201,600 during Friday’s auction.

In honour of Princess Diana, who died in 1997, Shanks painted a second full-length version in 2010.

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The auction house describes the original full-length painting as showing the “emotional toll of Diana’s public life in the mid-1990s, but also her inner-resilience.”