Ludwig Deutsch's The Palace Guard will lead Sotheby's Orientalist sale in London on April 21 with an £80,000-120,000 ($119,035-178,552) estimate.
Deutsch was an Austrian-born painter who lived and worked in Paris for most of his life.
He was a devotee of Orientalism, the romanticising of the exotic east that provided inspiration for many 19th century western artists.
The 1893 work depicts a Nubian sentry standing guard and displays a staggering level of detail.
Sotheby's comments: "Although little is known of the artist's working methods, it is likely that only the use of a magnifying glass would have allowed the artist to achieve the extremely fine level of detail visible in the present work, with every link in the figure's chainmail individually rendered…
"Deutsch's Egyptian subjects met with huge critical acclaim: in 1900 Deutsch was awarded a gold medal at the Exposition Universelle, and later the Chevalier de la Legion."
Fausto Zonaro's Bayram (the Celebration) is expected to make £350,000-450,000 ($520,779-669,573).
Zonaro described the spectacle, a street festival, which he witnessed firsthand in Istanbul: "Bringing together all the materials that I could, I start on a painting on the subject of Bayram.
"The drum is coming, and behind it the renowned Armenian who expertly plays the zurna. The dance begins and the young men link arms and arrange themselves in rows waiting for the beat of the drum.
"And then slowly, their movement becomes more exuberant, they get faster, with tiny steps the tiny swaying movements begin."
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