But, were it not for the Este documents, no trace would remain of the paintings that have disappeared: the paintings in the library of the Pico family at Mirandola; those in the Sacrati chapel, in the church of San Domenico in Ferrara; and in the chapel at Belriguardo. Paradoxically, the pictures that have survived to this day are shrouded in total silence. The sole exception concerns a masterpiece from the artist's first mature period, and the certainty with which this work can be dated has contributed to the chronological seriation of numerous other works: the Saint George and the Princess that, together with an Annunciation, adorned the antæ of the organ in Ferrara Cathedral.
In this regard the documents of the cathedral workshop tell us that on 11 June 1469 Tura received one hundred and eleven liras for having completed the four canvases to be mounted on the antae of the instrument. The organ, commissioned in 1465 by Bishop Lorenzo Roverella from Giovanni da Mercatello, the master organ maker, was installed in the church by March 1468 and was complete with its painted antæ by June 1469.
All in all the various phases of construction took four years and cost over five hundred golden ducats, a sum commensurate with the decorative and musical qualities of the instrument. Its acoustical qualities were so remarkably good that, a few months after, it was transferred from the apse to the central nave, behind the altar of the twelve Apostles, where it remained until it was dismantled and replaced in the early 18th century.
The antæ painted by Tura remained attached to the organ right to the end: after it was dismantled, they were first hung at the sides of the choir before being moved again, this time to the sacristy.
In the meantime swingeing restoration had led to alterations in the original colours and style while the features of the figures were changed.
Furthermore the canvases had been removed from their original stretchers and reassembled in pairs, with disastrous results for the Annunciation, which had not been conceived to be viewed from the front.
The 18th century restorer managed to botch the job even more by sewing the canvases together and by reducing to one the columns that delimited the two scenes, the result being a claustrophobic compression of the space. Luckily, the damage was remedied by successive restorers.
But let's take a more detailed look at what Tura painted. The selection of his subjects was partly conditioned by the intended location: the fact that the antæ could be opened or closed meant that the scene depicted on the inner sides of the antae had to be divided into two parts. One suitable response to this requirement was to depict saints, generally chosen from the ranks of the titular saints, but also Annunciations, which made it possible to separate the images of Gabriel and the Virgin without losing the narrative thread of the scene.
Tura's choice may therefore be collocated within concise iconographical practice. The decision to illustrate the external face of the antæ with the episode of Saint George and the dragon reveals more specific lies with Ferrara, insofar as St George is the patron saint of the city. But the choice was motivated by other factors more intimately bound up with the historical contingencies of the years in which the paintings were made.
The connection, sanctioned by medieval tradition, between the slaying of the dragon (whose breath infected the air and was a cause of death) and the redeeming work of man (who reclaimed the marshlands thus averting the risk of pestilence) would seem an allusion to the magnum opus of Borso d'Este, which was on the way to completion at that time, thus establishing an ideal connection between the duke and the saint who dealt the monster its death blow.
In addition, an important series of contextual figurative elements make the episode seem an allusion to the necessity of the crusades as a Christian response to the Turkish scourge, in accordance with the identification between Saint George the crusader. This need had become more pressing alter the fall of Constantinople in 1453. Faced with the expansionist policies of Mohammed II, Pope Pius II had made serious attempts to pacify the warring Italian states in order to launch a new crusade.
The intimate friendship between Lorenzo Roverella and Pius II makes it plausible that the commissioning of the cathedral organ was intended not only to commemorate the deceased pope, but above all to retable the notion of a crusade. While the iconographic and iconological background of the work is rooted in Ferrara. the same can not be said of the figurative references and the geographical matrix.
What emerges here are above all echoes of Padua, and of Mantegna in particular, the same echoes that resound throughout Tura's earlier work. But the play of stylistic assonances cannot, in any case, make us lose sight of a fundamental fact: the antæ of the organ in Ferrara are the expression of an artistic maturity that springs from the highly personal cadences in the vital energy of the figures, in the deliberately expressionistic forzature, in the robust linearity of the drapes, and in certain physiognomic details.