Virgin territory

Renaissance Siena was often overshadowed by more affluent Florence. Yet the city's art, in its devotion to Mary, had a feminine power equal to that of its more aggressive, masculine rival, argues Frances Stonor Saunders
Renaissance Siena
Domenico Beccafumi's Marcia, probably dating from 1520-1525. Photograph: The National Gallery PR

The Black Death, with all its pestilential potency, arrived on the Italian peninsula in early 1348 and, within a few months, some towns and cities had lost almost all their inhabitants. In Venice and Pisa, at least three-quarters died. Florence was so devastated that, for a long time, the disease was known as "the plague of Florence". In Siena, it raged from April until October and, according to one chronicler, 80,000 people died in those seven months, among them the great painters Ambrogio and Pietro Lorenzetti. The corpses, swollen with buboes, were pitchforked into common graves "like layers of lasagne". Work on Siena's cathedral - intended to rival the duomo of Florence in magnificence - was halted. Its truncated transept still stands as witness to the plague's abrupt intrusion into human plans. So do the many chronicles that end suddenly at this time, as their authors succumbed to the deadly miasma. Giovanni Villani wrote "and this pestilence lasted until -", but he died before he could fill in the blank. The present, as well as the future, seemed literally to be vanishing.

The plague followed a wave pattern, advancing and receding over the following decades, until it became known simply as "the accustomed mortality". Italy did not recover to its pre-plague population level until the middle of the 16th century. The demographic crisis was exacerbated by major climate change, as colder and wetter weather wiped out harvests and provoked widespread famines.

It was with some justification, then, that Barbara Tuchman described this period as "calamitous". But the designation obscured her own warning not to favour "the overload of the negative, the disproportionate survival of the bad side". Successive historians have ransacked the thesaurus of apocalypse, leaving us in a storm of gloom when we contemplate the late Middle Ages. Plague, sword and famine were the sole constants - the only motivation, even - in a disintegrating society. Central authority was dead. This was an age collapsing under the weight of its own decomposition.

There are other, competing narratives that challenge this view - narratives not of existential desperation, but of recovery, expansion and creativity. The Lorenzetti brothers, two of the most sought-after painters in Italy, were indeed dead, and this marked the end of the first Sienese School. But they were succeeded by Francesco di Giorgio, Domenico Beccafumi, Neroccio de' Landi and Matteo di Giovanni. In 1492, Ambrogio Lorenzetti's allegorical fresco cycle Good and Bad Government was already being restored, compelling evidence of a desire to celebrate and renew positive representations of collective identity. But the idea of a "waning" or "expiring" Middle Ages has proved hard to shake. This is because the cultural theory of the Renaissance, driven as it is by a biological imperative ("rebirth"), demands a death.

The term rinascimento was first supplied by Giorgio Vasari, in his Lives of the Most Excellent Painters, Sculptors and Architects, published in 1550. A hugely entertaining collection of anecdotes and gossip (we learn of Fra Lippo Lippi's bestial appetites, Andrea del Castagno's rancour towards other artists), Vasari's work offered nothing as grand - or reductive - as a theory of art, but it became, and remains, the ur-text of Renaissance art history. Vasari, court artist to the Grand Duke Cosimo de' Medici, advanced a kind of shorthand in which the Renaissance was synthesised as a Florentine invention, engendered by a distinct genealogy of Florentines from Giotto to Michelangelo.

Appearing at the moment when Florence conquered Siena to form the grand duchy of Tuscany, the Lives provided the textual commentary to crown an energetic propaganda campaign of Florentine pre-eminence. This was the culmination of a long and bitter struggle, a slugfest of military and economic wars of attrition in which all the city states had been embroiled. Much slower to reassert itself in the wake of the plague and now soundly trounced by its historic rival, Siena, a "star of the first order" in the 13th and early 14th centuries, devolved into a second-rate power of middling importance. The Sienese, it was said, were "like the inhabitants of the middle floor of a shaky house, tormented by the piss of their neighbours upstairs and smoked out by the people below".

Siena's decline was real (at one point, the public debt was so acute that the city resorted to selling off items such as mallets, buckets and lanterns from its stores), and one from which it would never recover. The international component of its economy had largely disappeared. The great banks of the Gallerani, Malavolti, Tolomei and Buonsignori had all failed and were not replaced by a new generation. By the 15th century, Siena's proud mercantile rhetoric finally disappeared, replaced by an aristocratic ethic, an attitude characterised by disdain for business and attachment to the life of the landed noble.

In Florence, meanwhile, the financial and cultural capital was growing, more than enough to fund those artists whose works extolled the integrity and vitality of the new territorial state. Their brushes and chisels tipped with the gold florins of the ruling elite, Masaccio, Mantegna, Pisanello, Uccello, Donatello, Ghiberti, Michelangelo painted or sculpted their way into the Renaissance. The Florentine juggernaut rolled on relentlessly towards ever-greater refinement in naturalism and perspective, while Siena, the argument goes, just couldn't keep up. Its art was underdeveloped, backward-looking, frankly medieval.

As Milan Kundera has observed, it's in the nature of art to be unfair, and art history is therefore the history of injustice. Once established, the dismissal of Sienese art as retardataire persisted because it went unchallenged. According to Martin Wyld, acting director of the National Gallery, its achievements have been "horribly neglected", its innovative features "fatally downplayed". A century ago, Bernard Berenson was of the same view. Writing from Siena in February 1897 to Isabella Steward Gardner, he exclaimed: "I have been here for a week looking at pictures eight hours a day. What pictures! Not known to silly fame, but real art, and if I live the day will come when some of them - many - will be sought for at least as much as Botticelli."

There's something slightly ridiculous about Berenson's tone, inflected as it is with the snobbery of the connoisseur ("real art", "silly fame"). It's like overhearing someone say, "I've discovered this marvellous little cheese shop in Pangbourne." For all his scholarly dedication to Sienese art in subsequent years, it can't be said that Berenson was successful in bringing its particular achievements to a broader audience. A Botticelli is still worth more than a Beccafumi. Or, to cheapen the coinage, Siena is still the Blackpool to Florence's Vegas.

The National Gallery exhibition Renaissance Siena: Art for a City, and the sumptuous catalogue that accompanies it, is the first major survey of Sienese art to be held in Britain since an exhibition organised by the Burlington Fine Arts Club in 1904. Its central claim is that there was not one, but several Renaissances going on, and that the Vasarian paradigm - where "great" art is that which progresses towards descriptive naturalism and mathematically plotted perspective - restricts our view of other developments.

This is not to say that Sienese artists didn't engage with these conventions, to the point of competing directly, and sometimes aggressively, with their Florentine counterparts. This competition was political as well as cultural, as exemplified by Siena's successful bid to lure Donatello, by then the most famous artist in Italy, away from Florence in 1457. A sensational propaganda coup, this marked the moment when Donatello's style was annexed to Siena's interests. He was immediately put to work to adorn the most important site for the civic religion of the city with a relief of the Virgin and Child. The relief was carved for a new chapel in the cathedral that would house the Madonna delle Grazie, an image with explicitly anti-Florentine associations. Paradoxically, the Sienese government at the same time actively encouraged the "Donatellisation" of art in the city, and Matteo di Giovanni and Benvenuto di Giovanni in particular introduced new, sculpturally derived elements into their works, quoting individual motifs and altering their stylistic approach to figures. This was a Florentine vocabulary, but, as curator Luke Syson argues in the exhibition catalogue, "it was absorbed within the Sienese dialect rather than repudiating it".

This "dialect" is perhaps best described as a visual language of ethereal, highly imaginative or "visionary" impulses. In contrast to (and occasionally in defiance of) the more rational rules of the humanist-led Renaissance, this mysticism was characterised by extraordinary spaces, by the continued use of sinuous, meandering line and of gilding, the gold worked with an almost infinite variety. Clearly referring to Siena's gothic past, this style could be defensive, a strategy for preserving that past in order to buttress the city's identity when it was under threat. Equally, we find artists updating this aesthetic, elaborating and rejuvenating it. Thus, Beccafumi's Stigmatisation of Saint Catherine of Siena combines the traditional techniques of sgraffito (scratching through the paint to reveal a gilded layer underneath) with the decidedly "modern" imperatives of buon disegno, or good design, and an almost rash disregard for refinement or polish.

Plague, famine, war, internal politics of baffling and often violent factionalism - all placed the very idea of a cohesive civic society under enormous stress. It is something of a miracle that a "Sienese" identity, straddled as it was on several fault lines, survived at all. Indeed, it was a belief in the miraculous - the patronage and governance of the Virgin Mary - that provided the cornerstone of this identity. In 1260, on the eve of the defeat of Florence at the battle of Montaperti, the Sienese had dedicated their city to the Virgin. The cult was amplified in 1359 when the hospital of Santa Maria della Scala bought relics from the imperial chapel at Constantinople that included parts of the Virgin's girdle and her veil. Acting in concert, the commune and church related a belief in this heavenly protector to fixed collective rites and symbols that together gave sacred meaning to the life of the community. Where necessary, this involved a degree of coercion: attendance at the vigil of the Feast of the Assumption (August 15) was mandatory for all citizens of Siena, their absence punishable by a fine.

The promptings of art were altogether more subtle, a highly refined fusion of stylistic iterations and specific, immediately decipherable messages. In Pietro Orioli's serene and opalescent Virgin and Child, the pattern on the Virgin's dress is accomplished using the traditional sgraffito technique, and she is flanked by saints each with a resonance for a member of one of the penitential confraternities in Siena - Jerome with his bruised chest (from beating his breast with a stone), and above all the great preacher and native hero Bernardino, instantly recognisable by his lack of teeth (he lost them all by the age of 40). Such images worked to instil in the viewer compassion, the quality of introspection, and a sense of shared identity.

It is this, the long visual tradition of Marian imagery - from Duccio di Buoninsegna and Simone Martini to Neroccio de' Landi and Domenico Beccafumi - that makes the art of Renaissance Siena so distinct. Where Florence is crammed with muscular displays of an antique and often sanguinary world (Mary McCarthy noted disapprovingly that its statues all seemed to be fighting, while Frieda Lawrence declared "This is a men's town"), in Siena the feminising influence of the Virgin is felt everywhere. She embraces the city's interests just as tenderly as she does her own infant Jesus. The belief that she offers her special protection still prevails; the dedication ceremony of 1260 has been repeated several times, most recently during the second world war as bombs were dropping nearby. "Away you evil one," the Virgin commands. "Get you behind me with your ill fortune. Leave this city of mine alone, in which live so many of my devotees." The National Gallery exhibition ignores the injunction to leave Siena alone, but it will surely gain many more devotees to the city's unique artistic achievements.

· Renaissance Siena: Art for a City is at the National Gallery, London WC2, until January 13. Details: 020 7747 2885