It is almost certain that he suffered the after-effects of a viral infection or an auto-immune disease, but as such things were unknown (and untreatable anyway) in those days, all that is recorded is that he suffered for eighteen months or so, before recovering enough to resume his usual life and activities. However, his mental stress can be seen in a series of fourteen paintings known as his Black Paintings in which his usual joyous use of colour and vibrant contrast is lacking. The images are dark, monotone and brooding, hinting at horrors if not explicitly displaying them. All the images were painted as murals originally, on the walls of the house to which he semi-retired in the early 1800s. These paintings were private to Goya: he never wrote of them and seldom even referred to them, and were, perhaps, his own effort to find some kind of cathartic release from his personal demons.

Some fifty years, after his death, the paintings were transferred – sometimes crudely – to canvas in order to preserve the works, and make them portable. La Leocadia, this image, is one of that series and it is thought that it depicts Goya's long-term companion and, it is widely presumed, lover and mother of one of his children. The image is not as dark as others in the series, and there are hints of flesh tones to her arms and face, and a blue sky overhead. But the woman in the painting – which is sometimes called The Seductress – is dressed in black, as though in mourning. Her pose, however, is almost insolently jaunty, a slouch that will be instantly recognised by any modern high-school teacher.

Her elbow rests atop a large unstructured boulder and her body curves in line with the boulder's bulging conformation, her feet casually crossed and the other arm slung behind her back – the whole pose redolent of boredom or ennui. The overall impression given is one of waiting, perhaps anticipating the removal of the vast shapeless boulder so that she can resume her own path? If taken that way, the image could be seen both as affirming of Leocadia's independence and feisty spirit, but also an acknowledgement (albeit an exaggerated one) on Goya's part that his failing body, his infirmities and his impending death and potential descent first into insanity and dementia were nothing more, at this stage of his life, than obstacles preventing his younger companion from soaring to heights unknown.

La Leocadia in Detail Francisco de Goya