Van Gogh painted five versions of Sunflowers in Arles in the late summer of 1888.
He was preparing for the arrival of Paul Gauguin, with whom he hoped to found an artists' community in the south of France.
These were meant to hang in Gauguin's room in the Yellow House.
He painted them quickly, in a state of excitement, in the heat of the Provençal summer.
The yellow is extraordinary, and also complicated.
Van Gogh used chrome yellow, which he knew would darken over time.
It has.
The original yellows were brighter and more varied; what you see now is a painting slowly, chemically altered by a century and a half.
Gauguin loved the series enough to make his own painting of Van Gogh at work on them.
Fun fact: this version was sold at Christie's in 1987 for £24.75 million — at the time the highest price ever paid for a painting at auction.
Van Gogh sold almost nothing during his lifetime, and died believing himself a failure.
He had been dead for 97 years.
