By the end of the fourteenth century, Spanish artists were beginning to absorb Italian influences and combined these with an interest in detail and anecdote more characteristic of Northern art. This hybrid style developed amid a disparate group of artists, among whom Nicolás Francés was an outstanding exponent. It is known from documents that he painted the high altar in the Cathedral of León in 1434 that was dedicated to Saint Froilán. Quite how he got this commission remains unknown, but it is possible to speculate that, like other artists, he had been attracted to Spain by the pilgrimage to Santiago de Compostela, and had found work along the way.
He painted another altarpiece dedicated to the Life of the Virgin and Saint Francis in La Bañeza, in León, now in the Prado Museum, Madrid. P.J. Sánchez Cantón, who wrote the only monograph on the artist (Maestro Nicolás Francés, Madrid, 1964), also attributed another altarpiece to him, dedicated to the Life of the Virgin in the Convent of Santa Clara de Tordesillas in Valladolid. Of undoubted French origin, as can be deduced from his name, Nicolás Francés trained in Burgundy, evident in his distinctive traits, such as the small scale of his figures - shown in the foreground - and his quirky use of perspective, the delineation of rather almond shaped eyes - evoking Giotto - and how he painted curly hair like a bonnet.
In A History of Spanish Painting (Harvard, 1947, IX, pp. 788-9), R.C. Post published a Mass of Saint Gregory in the Museum of Fine Arts, Boston, as a fully autograph work by Nicolás Francés. He did not mention the measurements, but considered it to form part of the predella of an altarpiece. The present lot is very close to the Boston painting. In both, the Saint appears in front of the altar, and is being helped by an altar boy during the consecration of the Host, at the moment when the Risen Christ appears, surrounded by the symbols of the Passion. The only significant difference between the two works is that in the present lot there are fewer symbols of the Passion; however, the quality is excellent and the details are very close to those of the panels remaining in the Cathedral of León, which formed part of the high altarpiece that was dismantled in 1740 to make way for a Baroque equivalent. According to Sánchez Cantón some of the fragments of this altarpiece were sent to humble local churches near León de Aldea de Oncina and Trobajo del Camino. He questions the whereabouts of the thirteen missing larger panels (measuring 152 x 272 cm.), speculating whether they were broken down or lost.
It is very easy to suppose that the predella of that altarpiece underwent the same fate, and given its dimensions it is quite possible that the present panel formed part of that dismantled altarpiece: firstly, the unusual perspective of this painting is the same as that of the Presentation of the Virgin in the León altarpiece, as is the design of the tiled floor; secondly, the clothes of the altar boy assisting Saint Gregory reappear in other scenes from this altarpiece, especially those figuring the translation of Santiago; thirdly, the figures, the brocades of the cope and the bonnet-style curly hair are repeated throughout the oeuvre of Nicolás Francés, especially in the León altarpiece. All this points to the present Mass of Saint Gregory being a work by the maestro, coming from the same period in which he painted the altarpiece of the Cathedral of León, and moreover it is very probable that the present, beautifully preserved, panel was part of the predella of that same altarpiece.