The highly anticipated auction of New York philanthropist Brooke Astor's estate at Sotheby's was highlighted yesterday (September 25) by the sale of a John Frederick Lewis artwork.

A Memlook Bey, Egypt was exhibited at London's Royal Academy in 1869

The sale saw 95% of its 901 lots of furniture, art, jewellery and silverware sold, and had already exceeded its low estimate after the first of four sessions. It went on to beat its $9.7m high valuation by 93.8%, achieving a total realisation of $18.8m.

In a continuation of Mrs Astor's philanthropic work, all proceeds from the sale will benefit charitable causes including the New York Public Library, Metropolitan Museum of Art, Pierpont Morgan Library and Animal Medical Centre of New York.

Leading bids was John Frederick Lewis' A Memlook Bey, Egypt, which is a brilliant representation of the artist's orientalist style. The piece was created following a period of almost a decade living in Egypt, during which Lewis made countless sketches of traditional life. On his return to England, the lavish colours and exotic nature of his work saw his dramatic rise to fame.

A Memlook Bey, Egypt was one of the artist's five exhibits at London's Royal Academy in 1969, four years after he received his prestigious election. It sold for $1.59m, achieving an impressive 218.9% increase on its $500,000 high estimate.

Also among the art highlights was a classic depiction of Venice from Canaletto, which soared to $1.2m, against a $300,000-500,000 estimate, showing a 140.5% increase. The artist's New horse Guards is expected to beat the $1.9m record for his work on October 17, when it sells at a Vienna auction.

Jewellery from Astor's personal collection was topped by her platinum, emerald and diamond engagement ring that sold for $1.2m, against an estimate of just $150,000. The 701.6% increase in value was boosted by its importance to Mrs Astor as well as its presence in Cecil Beaton's photographs of the resulting celebration.