Most history buffs know that Winston Churchill was a passionate amateur painter, but the rest of the world — and perhaps many of the buffs — may be surprised to learn that Churchill’s artwork is greatly sought after.

On April 23, Bonhams will sell the great man’s “Sunset over the Atlas Mountains,” painted in 1935–36 while Churchill was in Marrakech, Morocco. He gave the small work, which measures 20 by 24 inches, to his daughter, and it remained in the family until 1992. According to Bonhams’s European paintings expert Malcolm Walker, who secured the picture for the sale, prices for Churchill’s watercolors have been rising rapidly for more than a year now. Bonhams estimates the picture could sell for as much as $600,000 — an impressive price for an amateur painter whom no one could seriously call an “outsider artist.”

High prices for Churchill began in 2006, reaching their zenith last July when Sotheby’s sold a Churchill painting for more than $2 million.

With that in mind, the Bonhams number no longer seems so exuberant. Even the subject matter has seen higher prices. His 1948 picture titled “Marrakech” sold for nearly $1 million four months ago. Churchill himself would have appreciated the value placed upon his Moroccan landscapes. He was exceptionally fond of the view from Marrakech, and returned there often, once on a trip with President Roosevelt during World War II.

Indeed, war was the cause of Churchill’s career as a painter. He first dabbled with watercolors during a period of enforced idleness in 1915, when he was forced out as First Lord of the Admiralty after the disastrous campaign at Gallipoli. Though he picked up painting as a diversion, he pursued it — often seeking the advice of established artists in his social circle — for decades after.

The painting will be on display at Bonhams April 19–22.