The subject was not invented from imagination or literary source. Stubbs saw a lion attack a horse himself, on a stop in Morocco while sailing back to England from Rome in 1755, and the memory stayed with him long enough to become one of his most repeated subjects^[1]. He returned to the composition across a series of paintings rather than settling on one definitive version, adjusting the horse's pose and the surrounding darkness from canvas to canvas while keeping the basic confrontation, a white horse against a dark lion in open wilderness, constant throughout.

Stubbs earned his reputation for horses the hard way. He dissected horses himself over a period of grinding, methodical work, producing anatomical studies detailed and disciplined enough that later critics have placed them alongside Leonardo da Vinci's own dissections for their combination of scientific rigour and visual intelligence^[2]. He published the results in 1766 as Anatomy of the Horse, after he had already moved to London and quickly become the country's leading painter of horses, portraits typically showing a named animal with its owner or groom in attendance^[1]. That anatomical knowledge, built from years of unglamorous dissection rather than observation alone, is what makes the horse's musculature and terror convincing in the lion-attack pictures rather than merely dramatic.

Most of Stubbs's income came from portraits of specific, named horses commissioned by owners proud of a winning racer or a valuable stud animal. The lion-and-horse paintings are a different kind of picture entirely, made to provoke fear rather than admiration. In one well documented version from 1770, close in spirit to this canvas, the lion's dark, powerful legs rip into the horse's back with an almost casual violence while storm clouds gather overhead, the whole scene built deliberately to produce what contemporary aesthetic theory called the sublime, a horror the viewer experiences at a safe distance^[1]. The white horse stood for goodness and vulnerability against the lion's darkness, a moral contrast layered onto what began as something Stubbs had actually watched happen.