This was one of the sketches for a tapestry cartoon that was never executed, due to the death of Charles III, who had commissioned them. It was among the sketches sold to the Duke of Osuna in 1799.
The scene represents the most popular festival in the Madrid calendar, which is still celebrated on 15 May, the feast day of the city's patron saint, Isidore the Labourer.
In a letter to his friend Zapater in Saragossa, Goya wrote of the difficulties of such a subject especially as he had to finish this painting by the saint's day 'with all the bustle of the court'. It is in fact a rare example of a landscape by Goya, taken from the far side of the Manzanares River with the city's landmarks on the horizon, and in the foreground the crowds amusing themselves as at a fair, the pilgrims hard to distinguish among the animated crowds. Goya's viewpoint must have been the Hermitage of San Isidro, the goal of the pilgrimage. The building in Goya's painting (also designed as a sketch for a tapestry cartoon), is still preserved, marking the spot where the saint struck a well of water with healing powers. On a tiny scale, Goya has included the pilgrims lining up to enter the church, a picnic scene and a group at the miraculous well. Many years later Goya was to decorate the walls of his country house, the Quinta del Sordo, built not far from the Hermitage, with a nightmare vision of The Pilgrimage to San Isidro.
In his Handbook, Richard Ford described the pilgrimage as it was in his day: 'It is a truly Spanish and charming scene, far surpassing our Easter Monday at Greenwich, not merely in fun but piety, for this is a religious pilgrimage; thus their wise church renders their acts of devotion sources of enjoyment to its believers.'